Prince Harry will attend the London Marathon this weekend despite the bombings at the Boston Marathon.
Security for the major sporting event in the capital will be reviewed following yesterday's terror attack in the US which left at least three people dead.
But Harry, who is patron of the London Marathon Charitable Trust, will still will make the presentations to the winners of the various races including the elite men and women events.
Prince Harry poses with Mary Keitany and Wilson Kipsang, winners of the Men's and Women's Elite Race after the London Marathon in 2012.
The prince will also meet a selection of volunteers involved with the running of the annual event and members of the St John Ambulance.
A St James's Palace spokesman confirmed that the prince would be attending the marathon as planned but declined to comment further, he said: "As far as we're concerned there's nothing to suggest any change."
When asked about security arrangements he said that was a matter for the police and the organisers of the event.
When personal safety may be at risk the royal family follow the advice of the police and security officials.
Security for the London Marathon on Sunday will be reviewed following the explosions, Metropolitan Police Chief Superintendent Julia Pendry, the event commander for the race, said.
Sports minister Hugh Robertson told the BBC Radio 4 Today programme he was "absolutely confident" that the London event could be kept safe.
GRAPHIC WARNING: Boston Marathon explosion
GRAPHIC WARNING: Boston Marathon explosion
(01 of128)
In this photo provided by The Daily Free Press and Kenshin Okubo, people react to an explosion at the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Daily Free Press, Kenshin Okubo) MANDATORY CREDIT (credit:AP)
(02 of128)
Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion Monday, April 15, 2013 in Boston. Two bombs exploded near the finish line of the marathon on Monday, killing at least two people, injuring at least 22 others and sending authorities rushing to aid wounded spectators. (AP Photo/Charles Krupa) (credit:AP)
(03 of128)
Boston police clear an area following an explosion near the finish line of the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/Charles Krupa) (credit:AP)
(04 of128)
Medical personnel work outside the medical tent in the aftermath of two blasts which exploded near the finish line of the Boston Marathon in Boston, Monday, April 15, 2013. (AP Photo/Elise Amendola) (credit:AP)
(05 of128)
An unidentified Boston Marathon runner, center, is reunited with loved ones near Copley Square following an explosion in Boston Monday, April 15, 2013. (AP Photo/Winslow Townson) (credit:AP)
(06 of128)
Medical workers aid an injured woman at the finish line of the 2013 Boston Marathon following two explosions there, Monday, April 15, 2013 in Boston. Two bombs exploded near the finish of the Boston Marathon on Monday, killing at least two people, injuring at least 23 others and sending authorities rushing to aid wounded spectators. (AP Photo/Charles Krupa) (credit:AP)
(07 of128)
Workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Boston Herald, Stuart Cahill) MANDATORY CREDIT (credit:AP)
(08 of128)
In this photo provided by The Daily Free Press and Kenshin Okubo, people react to an explosion at the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Daily Free Press, Kenshin Okubo) MANDATORY CREDIT (credit:AP)
(09 of128)
In this photo provided by The Daily Free Press and Kenshin Okubo, people react to an explosion at the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Daily Free Press, Kenshin Okubo) MANDATORY CREDIT (credit:AP)
(10 of128)
In this photo provided by The Daily Free Press and Kenshin Okubo, people assist an injured after an explosion at the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Daily Free Press, Kenshin Okubo) MANDATORY CREDIT (credit:AP)
(11 of128)
Medical workers aid an injured woman at the scene of a bomb blast near the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two bombs exploded near the finish line of the Boston Marathon on Monday, killing at least two people and injuring at scores of others (AP Photo/Charles Krupa) (credit:AP)
(12 of128)
Medical workers aid injured people at the finish line of the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two bombs exploded near the finish line of the Boston Marathon on Monday, killing at least two people and injuring dozens of others (AP Photo/Charles Krupa) (credit:AP)
(13 of128)
Runners who were diverted from the race course walk on the Commonwealth Mall two blocks from the site of an explosion at the finish line of the Boston Marathon in Boston, Monday, April 15, 2013. Two bombs exploded near the finish line of the Boston Marathon on Monday, killing at least two people and injuring at least 23 others. (AP Photo/Michael Dwyer) (credit:AP)
(14 of128)
Una mujer llora afectada por una explosión mientras caminan cerca de la línea de meta de la Maratón de Boston el lunes 15 de abril de 2013. Dos bombas estallaron el lunes causando la muerte de dos personas y heridas a otras 50, informó la Policía de Boston. (AP Foto/Josh Reynolds) (credit:AP)
(15 of128)
An armed FBI agent passes a Boston police officer following an explosion at the finish line of the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/Josh Reynolds) (credit:AP)
(16 of128)
A firefighter tends to an injured man following an explosion near the finish line of the Boston Marathon in Boston, Monday, April 15, 2013. (AP Photo/Michael Dwyer) (credit:AP)
(17 of128)
One of the blast sites on Boylston Street near the finish line of the 2013 Boston Marathon is investigated by a person in a protective suit in the wake of two blasts in Boston, Monday, April 15, 2013. (AP Photo/Elise Amendola) (credit:AP)
(18 of128)
Firefighters tend to a man following an explosion at the finish line of the Boston Marathon in Boston, Monday, April 15, 2013. Two bombs exploded at the Boston Marathon finish line Monday killing at least two people injuring dozens. (AP Photo/Michael Dwyer) (credit:AP)
(19 of128)
In this photo provided by The Daily Free Press and Kenshin Okubo, people react to an explosion at the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Daily Free Press, Kenshin Okubo) MANDATORY CREDIT (credit:AP)
(20 of128)
Two people walk down the sidewalk as Boston police clear the area in Copley Square in the aftermath of two blasts which exploded near the finish line of the Boston Marathon in Boston Monday, April 15, 2013. The explosions Monday killed at least two people and injured dozens. (AP Photo/Elise Amendola) (credit:AP)
(21 of128)
This photo provided by Bruce Mendelsohn shows the scene after two explosions occurred during the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/ Bruce Mendelsohn) MANDATORY CREDIT (credit:AP)
(22 of128)
Medical workers respond following an explosion at the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Boston Globe, David L Ryan) MANDATORY CREDIT (credit:AP)
(23 of128)
Boston police direct runners who were diverted from the race course following an explosion at the finish line of the Boston Marathon in Boston, Monday, April 15, 2013. (AP Photo/Michael Dwyer) (credit:AP)
(24 of128)
Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Boston Globe, David L Ryan) MANDATORY CREDIT (credit:AP)
(25 of128)
Medical workers aid injured people at the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Boston Globe, David L Ryan) MANDATORY CREDIT (credit:AP)
(26 of128)
Blood from victims covers the sidewalk on Boylston Street, at the site of an explosion during the 2013 Boston Marathon in Boston, Monday, April 15, 2013. At the right foreground is a folding chair with the design of an American flag on the cover. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/Charles Krupa) (credit:AP)
(27 of128)
Chris Darmody, right, holds his wife Sue in Boston, Monday, April 15, 2013. Chris says he was waiting for Sue when an explosion detonated near his location at the finish line of the Boston Marathon. The couple were later reunited after all runners were diverted from the course. (AP Photo/Michael Dwyer) (credit:AP)
(28 of128)
Emergency responders comfort a woman on a stretcher who was injured in a bomb blast near the finish line of the Boston Marathon Monday, April 15, 2013 in Boston. Two bombs exploded in the packed streets near the finish line of the marathon on Monday, killing at least two people and injuring more than 80, authorities said. (AP Photo/Jeremy Pavia) (credit:AP)
(29 of128)
Emergency responders aid a woman on a stretcher who was injured in a bomb blast near the finish line of the Boston Marathon Monday, April 15, 2013 in Boston. Two bombs exploded in the packed streets near the finish line of the marathon on Monday, killing at least two people and injuring more than 80, authorities said. (AP Photo/Jeremy Pavia) (credit:AP)
(30 of128)
Emergency responders comfort a woman on a stretcher who was injured in a bomb blast near the finish line of the Boston Marathon Monday, April 15, 2013 in Boston. Two bombs exploded in the packed streets near the finish line of the marathon on Monday, killing at least two people and injuring more than 80, authorities said. (AP Photo/Jeremy Pavia) (credit:AP)
(31 of128)
Rescue personnel aid injured people near the finish line of the 2013 Boston Marathon following explosions in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Boston Herald, Stuart Cahill) (credit:AP)
(32 of128)
Rescue personnel aid injured people near the finish line of the 2013 Boston Marathon following explosions in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Boston Herald, Stuart Cahill) (credit:AP)
(33 of128)
Injured people and debris lie on the sidewalk near the Boston Marathon finish line following an explosion in Boston, Monday, April 15, 2013. (AP Photo/MetroWest Daily News, Ken McGagh) MANDATORY CREDIT (credit:AP)
(34 of128)
As Boston Marathon runners walk by, SWAT team members stand guard near the finish line in Boston Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. ( (AP Photo/Winslow Townson) (credit:AP)
(35 of128)
People react to an explosion at the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Boston Herald, Stuart Cahill) BOSTON GLOBE OUT; METRO BOSTON OUT; MAGS OUT; (credit:AP)
(36 of128)
Investigators shine flashlights at one of the blast sites on Boylston Street near the finish line of the 2013 Boston Marathon in the wake of two blasts in Boston Monday, April 15, 2013. (AP Photo/Elise Amendola) (credit:AP)
(37 of128)
In this image from video provided by Ryan Hoyme, the second explosion can be seen in the distance as smoke from the first explosion surrounds spectators exiting the stands during the Boston Marathon in Boston, Monday, April 15, 2013. (AP Photo/Ryan Hoyme) (credit:AP)
knocked down runner(38 of128)
Bill Iffrig, 78, lies on the ground as police officers react to a second explosion at the finish line of the Boston Marathon in Boston, Monday, April 15, 2013. Iffrig, of Lake Stevens, Wash., was running his third Boston Marathon and near the finish line when he was knocked down by one of two bomb blasts. (AP Photo/The Boston Globe, John Tlumacki) (credit:AP)
(39 of128)
A Boston Marathon runner leaves the course crying near Copley Square following an explosion at the finish line in Boston on Monday, April 15, 2013. (AP Photo/Winslow Townson) (credit:AP)
(40 of128)
People react as an explosion goes off near the finish line of the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions went off at the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/The Boston Globe, David L Ryan) MANDATORY CREDIT (credit:AP)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(41 of128)
BOSTON, MA - APRIL 15: A runner embraces another woman on the marathon route near Kenmore Square after two bombs exploded during the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Alex Trautwig/Getty Images) (credit:Getty Images)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(42 of128)
BOSTON, MA - APRIL 15: A runner reacts near Kenmore Square after two bombs exploded during the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Alex Trautwig/Getty Images) (credit:Getty Images)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(43 of128)
BOSTON, MA - APRIL 15: A runner embraces another woman near Kenmore Square after two bombs exploded during the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Alex Trautwig/Getty Images) (credit:Getty Images)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(44 of128)
BOSTON, MA - APRIL 15: A woman is loaded into an ambulance after he was injured by one of two bombs exploded during the 117th Boston Marathon near Copley Square on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Jim Rogash/Getty Images) (credit:Getty Images)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(45 of128)
BOSTON, MA - APRIL 15: A woman is loaded into an ambulance after he was injured by one of two bombs exploded during the 117th Boston Marathon near Copley Square on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Jim Rogash/Getty Images) (credit:Getty Images)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(46 of128)
BOSTON, MA - APRIL 15: A woman, with blood on fingers, is loaded into an ambulance after being injured after two bombs exploded on the marathon route on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Jim Rogash/Getty Images) (credit:Getty Images)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(47 of128)
BOSTON, MA - APRIL 15: A woman looks at the blood on her hands as she is loaded into an ambulance after being injured after two bombs exploded on the marathon route on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Jim Rogash/Getty Images) (credit:Getty Images)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(48 of128)
BOSTON, MA - APRIL 15: Two blood stained feet of a man hang outside an ambulance outside a medical tent located near the finish of the 117th Boston Marathon after two bombs exploded on the marathon route on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Jim Rogash/Getty Images) (credit:Getty Images)
(49 of128)
Boston police ask people to leave the area in Copley Plaza in the aftermath of two blasts which exploded near the finish line of the Boston Marathon in Boston Monday, April 15, 2013. (AP Photo/Elise Amendola) (credit:AP)
(50 of128)
Paramédicos asisten a un hombre herido después de una explosión en Boston el Lunes 15 de Abril de 2013. Dos bombas estallaron cerca de la línea de meta del maratón de Boston, causaron dos muertos y 22 heridos, dijeron la policía y los organizadores de la competición. (AP Foto/The Boston Globe, David L. Ryan) (credit:AP)
(51 of128)
Uniformed Division Secret Service officers stand watch on the sidewalk in front of the White House looking north from Pennsylvania Avenue during heightened security following the explosions in Boston, Monday, April 15, 2013 in Washington. (AP Photo/Charles Dharapak) (credit:AP)
(52 of128)
Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two explosions near the finish of the Boston Marathon on Monday, killing at least two people, injuring over 20 others. (AP Photo/Charles Krupa) (credit:AP)
(53 of128)
Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/Charles Krupa) (credit:AP)
(54 of128)
An unidentified Boston Marathon runner is comforted as she cries in the aftermath of two blasts which exploded near the finish line of the Boston Marathon in Boston, Monday, April 15, 2013. (AP Photo/Elise Amendola) (credit:AP)
Two Explosions Near Finish Line at Boston Marathon(55 of128)
First responders transport an injured woman in a wheelchair where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(56 of128)
First responders transport the wounded where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(57 of128)
First responders rush to help injured people after two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(58 of128)
First responders rush to where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(59 of128)
First responders rush to where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(60 of128)
First responders rush to where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Explosions At 117th Boston Marathon(61 of128)
BOSTON - APRIL 15: People on Boylston Street check their mobile devices for news of the explosions near the finish line at the 117th Boston Marathon. (Photo by Jim Davis/The Boston Globe via Getty Images) (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(62 of128)
First responders rush to where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Explosions At 117th Boston Marathon(63 of128)
BOSTON - APRIL 15: (EDITOR'S NOTE: THIS IMAGE CONTAINS GRAPHIC CONTENT) A person who was injured in an explosion near the finish line of the 117th Boston Marathon is taken away from the scene on a stretcher. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(64 of128)
BOSTON - APRIL 15: (EDITOR'S NOTE: THIS IMAGE CONTAINS GRAPHIC CONTENT) A person who was injured in an explosion near the finish line of the 117th Boston Marathon is taken away from the scene on a stretcher. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(65 of128)
Boston Police cordon off the finish line area where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Explosions At 117th Boston Marathon(66 of128)
BOSTON - APRIL 15: (EDITOR'S NOTE: THIS IMAGE CONTAINS GRAPHIC CONTENT) Destruction and injured people at the site of the one of the explosions that went off near the finish line of the 117th Boston Marathon. Barricades hindered the EMS from getting to the injured. (Photo by John Tlumacki/The Boston Globe via Getty Images) (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(67 of128)
First responders rush to where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(68 of128)
Runners and spectators flee from the scene where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(69 of128)
First responders tend to the wounded where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(70 of128)
First responders tend to the wounded where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(71 of128)
First responders load injured people into an ambulance where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(72 of128)
First responders tend to the wounded, including a young boy in a wheelchair, where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(73 of128)
Firemen carry an injured person where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(74 of128)
A runner with bloodstains on his body walks away from the scene where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(75 of128)
BOSTON, MA - APRIL 15: A man is loaded into an ambulance after he was injured by one of two bombs exploded during the 117th Boston Marathon near Copley Square on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Jim Rogash/Getty Images) (credit:Getty Images)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(76 of128)
BOSTON, MA - APRIL 15: A man is loaded into an ambulance after he was injured by one of two bombs exploded during the 117th Boston Marathon near Copley Square on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Jim Rogash/Getty Images) (credit:Getty Images)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(77 of128)
BOSTON, MA - APRIL 15: A man is loaded into an ambulance after he was injured by one of two bombs exploded during the 117th Boston Marathon near Copley Square on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Jim Rogash/Getty Images) (credit:Getty Images)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(78 of128)
BOSTON, MA - APRIL 15: A woman is loaded into an ambulance after he was injured by one of two bombs exploded during the 117th Boston Marathon near Copley Square on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Jim Rogash/Getty Images) (credit:Getty Images)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(79 of128)
BOSTON, MA - APRIL 15: A man is loaded into an ambulance after he was injured by one of two bombs exploded during the 117th Boston Marathon near Copley Square on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Jim Rogash/Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(80 of128)
BOSTON - APRIL 15: A Boston Marathon runner wanders through traffic at Boylston Street and Massachusetts Avenue after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by Jim Davis/The Boston Globe via Getty Images) (credit:Getty Images)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(81 of128)
BOSTON, MA - APRIL 15: A member of the bomb squad investigates a suspicious item on the road near Kenmore Square after two bombs exploded during the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Alex Trautwig/Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(82 of128)
BOSTON - APRIL 15: Two men look under bleachers for another device after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(83 of128)
BOSTON - APRIL 15: Emergency personnel respond to the scene after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(84 of128)
BOSTON, MA - APRIL 15: A member of the bomb squad investigates a suspicious item on the road near Kenmore Square after two bombs exploded during the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Alex Trautwig/Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(85 of128)
BOSTON - APRIL 15: Emergency personnel respond to the scene after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(86 of128)
BOSTON - APRIL 15: A second explosion goes off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(87 of128)
BOSTON - APRIL 15: A second explosion goes off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(88 of128)
BOSTON - APRIL 15: State Police cruisers sped toward Copley Place after two explosions downtown near the finish line of the 117th Annual Boston Marathon in Boston, Mass. on Monday, April 15, 2013. (Photo by Yoon S. Byun/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(89 of128)
BOSTON - APRIL 15: Runners who had not finished the race were stopped before the Massachusetts Avenue overpass on Commonwealth Avenue after two explosions went off near the finish line of the 117th Annual Boston Marathon in Boston, Mass. on Monday, April 15, 2013. (Photo by Yoon S. Byun/The Boston Globe via Getty Images) (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(90 of128)
First responders rush to where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(91 of128)
First responders transport an injured woman in a wheelchair where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(92 of128)
First responders transport the wounded where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(93 of128)
First responders rush to where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(94 of128)
First responders rush to help injured people after two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(95 of128)
First responders rush to where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(96 of128)
First responders rush to where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
Two Explosions Near Finish Line at Boston Marathon(97 of128)
First responders rush to where two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. Photographer: Kelvin Ma/Bloomberg via Getty Images (credit:Getty Images)
(98 of128)
A Boston police officer clears Boylston Street following an explosion at the finish line of the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria at the finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/Charles Krupa) (credit:AP)
(99 of128)
Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/Charles Krupa) (credit:AP)
(100 of128)
A Boston police officer wheels in injured boy down Boylston Street as medical workers carry an injured runner following an explosion during the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria at the marathon's finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/Charles Krupa) (credit:AP)
Explosions At 117th Boston Marathon(101 of128)
BOSTON - APRIL 15: (EDITOR'S NOTE: THIS IMAGE CONTAINS GRAPHIC CONTENT) A person who was injured in an explosion near the finish line of the 117th Boston Marathon is taken away from the scene in a wheelchair. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(102 of128)
BOSTON - APRIL 15: (EDITOR'S NOTE: THIS IMAGE CONTAINS GRAPHIC CONTENT) A person who was injured in an explosion near the finish line of the 117th Boston Marathon is taken away from the scene on a stretcher. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(103 of128)
BOSTON - APRIL 15: (EDITOR'S NOTE: THIS IMAGE CONTAINS GRAPHIC CONTENT) A person who was injured in an explosion near the finish line of the 117th Boston Marathon is taken away from the scene on a stretcher. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(104 of128)
BOSTON - APRIL 15: Emergency personnel respond to the scene after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(105 of128)
BOSTON - APRIL 15: Emergency personnel respond to the scene after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(106 of128)
BOSTON - APRIL 15: Two officials run away from the first explosion, right, on Boylston Street at the 177th Boston Marathon, April 15, 2013. (Photo by John Tlumacki/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(107 of128)
BOSTON - APRIL 15: Emergency personnel respond to the scene after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(108 of128)
BOSTON - APRIL 15: A man lays on the ground after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(109 of128)
BOSTON - APRIL 15: Emergency personnel respond to the scene after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(110 of128)
BOSTON - APRIL 15: (EDITOR'S NOTE: THIS IMAGE CONTAINS GRAPHIC CONTENT) A person who was injured in an explosion near the finish line of the 117th Boston Marathon is taken away from the scene in a wheelchair. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(111 of128)
BOSTON - APRIL 15: Emergency personnel respond to the scene after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(112 of128)
BOSTON - APRIL 15: Police officers with their guns drawn hear the second explosion down the street. The first explosion knocked down a runner at the finish line of the 117th Boston Marathon. (Photo by John Tlumacki/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(113 of128)
BOSTON - APRIL 15: (EDITOR'S NOTE: THIS IMAGE CONTAINS GRAPHIC CONTENT) A person who was injured in an explosion near the finish line of the 117th Boston Marathon is taken away from the scene in a wheelchair. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(114 of128)
BOSTON - APRIL 15: A second explosion goes off (rear) as a runner was blown to the ground by the first explosion near the finish line of the 117th Boston Marathon. (Photo by John Tlumacki/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(115 of128)
BOSTON - APRIL 15: A second explosion goes off (rear) as a runner was blown to the ground by the first explosion near the finish line of the 117th Boston Marathon. (Photo by John Tlumacki/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(116 of128)
BOSTON - APRIL 15: Police officers with their guns drawn hear the second explosion down the street. The first explosion knocked down a runner at the finish line of the 117th Boston Marathon. (Photo by John Tlumacki/The Boston Globe via Getty Images) (credit:Getty Images)
(117 of128)
Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. (AP Photo/Charles Krupa) (credit:AP)
(118 of128)
Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. (AP Photo/Charles Krupa) (credit:AP)
(119 of128)
In this image from video provided by WBZ TV, spectators and runners run from what was described as twin explosions that shook the finish line of the Boston Marathon, Monday, April 15, 2013, in Boston. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/WBZTV) MANDATORY CREDIT (credit:AP)
(120 of128)
Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. (AP Photo/Charles Krupa) (credit:AP)
(121 of128)
Medical workers wheel the injured across the finish line during the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/Charles Krupa) (credit:AP)
Explosions At 117th Boston Marathon(122 of128)
BOSTON - APRIL 15: Two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
Explosions At 117th Boston Marathon(123 of128)
BOSTON - APRIL 15: Two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images) (credit:Getty Images)
(124 of128)
A flag flies over the finish line as medical workers aid injured people following an explosion at the finish line of the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria at the finish line, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/Charles Krupa) (credit:AP)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(125 of128)
BOSTON, MA - APRIL 15: State police guard an area near Kenmore Square after two bombs exploded during the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Alex Trautwig/Getty Images) (credit:Getty Images)
Boston Explosion(126 of128)
Boston to a T @Boston_to_a_T 1hSecond explosion going off @ Coply Square. #marathonmonday @universalhub pic.twitter.com/rOQ9EnTkx1
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(127 of128)
BOSTON, MA - APRIL 15: A member of the bomb squad investigates a suspicious item on the road near Kenmore Square after two bombs exploded during the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Alex Trautwig/Getty Images) (credit:Getty Images)
Multiple People Injured After Explosions Near Finish Line at Boston Marathon(128 of128)
BOSTON, MA - APRIL 15: A member of the bomb squad investigates a suspicious item on the road near Kenmore Square after two bombs exploded during the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Photo by Alex Trautwig/Getty Images) (credit:Getty Images)