UPDATE: Kenyan officials say that an unknown number of hostages remain inside the Westgate centre, as security forces say they have "pinned down" the gunmen.

UPDATE: At least 39 are dead and more than 150 have been wounded in the assault, Kenya's president announced on national TV.

UPDATE: William Hague has warned that British Nationals have undoubtedly been caught up in the Nairobi attack.

UPDATE: Somali Islamist militant group al Shabaab has told the BBC that they carried out the attack in Nairobi.


At least 39 have been killed and upwards of 150 injured in a terrorist attack on a shopping mall popular with Westerners in the Kenyan capital of Nairobi. Reports suggest that the attackers may have taken hostages in the upmarket shopping centre, having threatened to kill any "non-Muslims".

William Hague said on Saturday night that British nationals were undoubtedly caught up in the "callous and cowardly and brutal" attack, adding: "We should be ready for that and aware of that".

SEE ALSO: Who Are Militant Group Al-Shabaab?

Earlier, Sir Simon Fraser, who works for the British Diplomatic Service, stoked fears that British nationals were caught up in the incident, tweeting: "@foreignoffice and @UKinKenya working hard on Nairobi shooting and hostage crisis to help all involved esp Brits."

A Downing Street spokesman said on Saturday: "The Prime Minister spoke to the President of Kenya, Uhuru Kenyatta, late this afternoon about the attack at Westgate shopping centre in Nairobi." The Foreign Office added: "We are in close touch with Kenyan authorities about the attack in Nairobi. Our urgent priority is the welfare of UK nationals in Kenya."

Al-Shabaab, also known as Harakat al-Shabaab al-Mujahideen (HSM), have claimed responsibility for the massacre. They wrote on their official Twitter account: "the Mujahideen entered Westgate Mall today at around noon".

Several men reportedly threw grenades into the Westgate Mall before opening fire indiscriminately around midday local time on Saturday. The mall, which has Israeli ownership and boasts many Western brands, including Nike and Bose, was holding a children’s day event at the time.

Reported by the Press Association, Elijah Kamau, a witness to the massacre, said that the attackers told all Muslims to go. "The gunmen told Muslims to stand up and leave. They were safe, and non-Muslims would be targeted," he said.

nairobi mall shooting

Injured children were carried out on trolleys

Speaking to the BBC, Hannah Chisholm, a Briton visiting the capital, said she and around 60 others barricaded themselves into a large storeroom.

She told the broadcaster: "We kept running to different places but the shots were getting louder so we barricaded ourselves along with about 60 others into a large storeroom. There were children hiding with us as well as someone who had been shot. The gunfire was loud and we were scared but at that point we thought the gunmen were thieves so we assumed they wouldn't try to reach the storeroom."

Arjen Westra also witnessed the attack. He said: "I could hear the gunfire moving towards the main entrance of the shopping mall, so some people ran out of our cafe in a kind of panic, and quite a number just fell down as flat as possible on the ground."

Reported by the Associated Press, witness Jay Patel said that he saw the gunmen with a group of people before entering the mall heavily armed. Another witness, 18-year-old Manish Turohit, said the attackers had AK-47s and vests with hand grenades. "They just came in and threw a grenade. We were running and they opened fire. They were shouting and firing," he said.

Hundreds trapped inside the mall made their way to the exits, many injured, including children. Staff used trolleys to wheel out the wounded. Nairobi police chief Benson Kibue has already called the incident a terrorist attack, while members of the Kenyan military have streamed to the scene.

(Story continues after the gallery)

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  • Relatives help a woman at the Nairobi City Mortuary after she identified the body of a victim of the mall attack in Kenya, Sunday, Sept. 22, 2013. Kenyan authorities said Islamic extremist attackers remain inside the upscale Kenyan shopping mall, holding an unknown number of hostages, after killing at least 39 and injuring 150 during Saturday's attack. (AP Photo/Khalil Senosi)

  • Sunday, Sept. 22, 2013: Nairobi, Kenya_ Relatives help a woman at the Nairobi City Mortuary after she identified the body of a victim of the Saturday attack at a mall. Kenyan authorities said Islamic extremist attackers remain inside the upscale Kenyan shopping mall, holding an unknown number of hostages, after killing and injuring scores of people in the attack. An assault by Islamic extremists at a Kenya mall, a suicide attack on a Pakistani church and assaults by suicide bombers targeting mourners at Shiite and Sunni funerals in Iraq have killed more than 250 people and injured at least 470 others since Saturday. (AP Photo/Khalil Senosi)

  • Saturday, Sept. 21, 2013: Nairobi, Kenya_ A security officer helps a wounded woman outside the Westgate Mall after gunmen opened fire and threw grenades. Kenyan authorities said Islamic extremist attackers remain inside the upscale Kenyan shopping mall Sunday, holding an unknown number of hostages, after killing and injuring scores of people the attack. (AP Photo/Khalil Senosi, File)

  • Saturday, Sept. 21, 2013: Nairobi, Kenya_Civilians who had been hiding during a gun battle hold their hands in the air as a precautionary measure before being searched by armed police leading them to safety, inside the Westgate Mall. Kenyan authorities said Islamic extremist attackers remain inside the upscale Kenyan shopping mall Sunday, holding an unknown number of hostages, after killing and injuring scores of people in the attack. (AP Photo/Jonathan Kalan, File)

  • Kenya security forces are seen behind a wall outside the Westgate Mall in Nairobi, Kenya Monday morning, Sept. 23, 2013. Kenya's military launched a major operation at the upscale Nairobi mall and said it had rescued "most" of the hostages being held captive by al-Qaida-linked militants during the standoff that killed at least 68 people and injured 175. (AP Photo/Jerome Delay)

  • Kenya security personnel, one in plain clothes, take cover outside the Westgate Mall in Nairobi, Kenya, Monday Sept. 23, 2013 after shooting started inside the mall. Kenya's military launched a major operation at the upscale Nairobi mall and said it had rescued "most" of the hostages being held captive by al-Qaida-linked militants during the standoff that killed at least 68 people and injured 175. (AP Photo/Sayyid Azim)

  • Kenya security forces are seen behind a wall outside the Westgate Mall in Nairobi, Kenya Monday morning, Sept. 23, 2013. Kenya's military launched a major operation at the upscale Nairobi mall and said it had rescued "most" of the hostages being held captive by al-Qaida-linked militants during the standoff that killed at least 68 people and injured 175. (AP Photo/Jerome Delay)

  • Kenya security personnel arrive in a land rover outside the Westgate Mall after firing started inside the mall in Nairobi, Kenya, Monday, Sept. 23, 2013. Kenya's military launched a major operation at an upscale Nairobi mall and said it had rescued "most" of the hostages being held captive by al-Qaida-linked militants during a two-day standoff that killed at least 68 people and injured 175. (AP Photo/Sayyid Azim)

  • Kenya Security personnel take cover outside the Westgate Mall after firing started inside the mall early Monday morning, Sept. 23, 2013. Kenya's military launched a major operation at the upscale Nairobi mall and said it had rescued "most" of the hostages being held captive by al-Qaida-linked militants during the standoff that killed at least 68 people and injured 175. (AP Photo/Sayyid Azim)

  • Kenyans wait to donate blood for victims in Sunday's terrorist attack on a shopping mall, at Uhuru Park in Nairobi, Kenya Monday, Sept. 23, 2013. Hostages being held by al-Qaida-linked terrorists in the mall have not been released despite an earlier statement from the military that "most" had been rescued, a person connected to the situation told The Associated Press on Monday. (AP Photo/Khalil Senosi)

  • People donate blood for injured persons in an attack at the Westgate Mall, at Uhuru Park in Nairobi, Kenya, Monday, Sept. 23, 2013. Hostages being held by al-Qaida-linked terrorists in the mall have not been released despite an earlier statement from the military that “most” had been rescued, a person connected to the situation told The Associated Press on Monday. Military helicopters circled over the mall at daybreak, when about five minutes of sustained gunfire broke out at the mall, a clear indication that at least one of the estimated 10 to 15 gunmen who attacked the mall when it was filled with shoppers Saturday was still on the loose. (AP Photo/Khalil Senosi)

  • People donate blood for injured persons in an attack at the Westgate Mall, at Uhuru Park in Nairobi, Kenya, Monday, Sept. 23, 2013. Hostages being held by al-Qaida-linked terrorists in the mall have not been released despite an earlier statement from the military that “most” had been rescued, a person connected to the situation told The Associated Press on Monday. Military helicopters circled over the mall at daybreak, when about five minutes of sustained gunfire broke out at the mall, a clear indication that at least one of the estimated 10 to 15 gunmen who attacked the mall when it was filled with shoppers Saturday was still on the loose. (AP Photo/Khalil Senosi)

  • Stephen, center, who lost his father in Saturday's attack at the Westgate Mall in Nairobi, Kenya, is comforted by relatives as he waits for the post mortem exam at the city morgue Monday, Sept. 23, 2013. Islamic extremist gunmen lobbed grenades and fired assault rifles inside Nairobi's top mall Saturday, killing dozens and wounding over a hundred in the attack. Early Monday morning gunmen remained holed up inside the mall with an unknown number of hostages. (AP Photo/Jerome Delay)

  • Stephen, center, who lost his father in Saturday's attack at the Westgate Mall in Nairobi, Kenya, is comforted by relatives as he waits for the post mortem exam at the city morgue Monday, Sept. 23, 2013. Islamic extremist gunmen lobbed grenades and fired assault rifles inside Nairobi's top mall Saturday, killing dozens and wounding over a hundred in the attack. Early Monday morning gunmen remained holed up inside the mall with an unknown number of hostages. (AP Photo/Jerome Delay)

  • Paramedics and police officers run outside the Westgate Mall in Nairobi after heavy shooting started Monday, Sept. 23, 2013. Kenya's military launched a major operation at the upscale Nairobi mall and said it had rescued "most" of the hostages being held captive by al-Qaida-linked militants during the standoff. (AP Photo/Sayyid Azim)

  • Armed police from the General Service Unit take cover behind a wall during a bout of gunfire, outside the Westgate Mall in Nairobi, Kenya Monday, Sept. 23, 2013. Hostages being held by al-Qaida-linked terrorists in a Nairobi mall have not been released despite an earlier statement from the military that "most" had been rescued, a person connected to the situation told The Associated Press on Monday. (AP Photo/Ben Curtis)

  • People take cover outside the Westgate Mall in Nairobi after heavy shooting started Monday, Sept. 23, 2013. Kenya's military launched a major operation at the upscale Nairobi mall and said it had rescued "most" of the hostages being held captive by al-Qaida-linked militants during the standoff. (AP Photo/Sayyid Azim)

  • A paramedic runs for cover outside the Westgate Mall in Nairobi after heavy shooting started Monday, Sept. 23, 2013. Kenya's military launched a major operation at the upscale Nairobi mall and said it had rescued "most" of the hostages being held captive by al-Qaida-linked militants during the standoff. (AP Photo/Sayyid Azim)

  • A Red Cross assistant helps a child outside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013, after gunmen threw grenades and opened fire during an attack that left multiple dead and dozens wounded. A witness to the attacks on the upscale shopping mall says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted. (AP Photo/Khalil Senosi)

  • A security guard helps a child outside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21 2013, after gunmen threw grenades and opened fire during an attack that left multiple dead and dozens wounded. A witness to the attacks on the upscale shopping mall says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted. (AP Photo/Khalil Senosi)

  • The mother and a security guard help a child outside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21 2013, after gunmen threw grenades and opened fire during an attack that left multiple dead and dozens wounded. A witness to the attacks on the upscale shopping mall says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted. (AP Photo/Khalil Senosi)

  • Security officers help a wounded woman outside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013, after gunmen threw grenades and opened fire during an attack that left multiple dead and dozens wounded. A witness to the attacks on the upscale shopping mall says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted. (AP Photo/Khalil Senosi)

  • An injured person is helped on his arrival at the Aga Khan Hospital in Nairobi after an attack at the Westgate Mall, an upscale shopping mall in Nairobi, Kenya Saturday Sept. 21, 2013, where shooting erupted when armed men staged an attack. A witness to the attacks says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted. Initial police reports had described the incident as a botched robbery. Witnesses say a half dozen grenades also went off along with volleys of gunfire in and around the mall. (AP Photo/Jason Straziuso)

  • An injured person is helped on his arrival at the Aga Khan Hospital in Nairobi after an attack at the Westgate Mall, an upscale shopping mall in Nairobi, Kenya Saturday Sept. 21, 2013, where shooting erupted when armed men staged an attack. A witness to the attacks says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted. Initial police reports had described the incident as a botched robbery. Witnesses say a half dozen grenades also went off along with volleys of gunfire in and around the mall. (AP Photo/Jason Straziuso)

  • An injured person arrives at the Aga Khan Hospital in Nairobi after an attack at the Westgate Mall, an upscale shopping mall in Nairobi, Kenya Saturday Sept. 21, 2013, where shooting erupted when armed men staged an attack. A witness to the attacks says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted. Initial police reports had described the incident as a botched robbery. Witnesses say a half dozen grenades also went off along with volleys of gunfire in and around the mall. (AP Photo/Jason Straziuso)

  • An injured person is helped on his arrival at the Aga Khan Hospital in Nairobi after an attack at the Westgate Mall, an upscale shopping mall in Nairobi, Kenya Saturday Sept. 21, 2013, where shooting erupted when armed men staged an attack. A witness to the attacks says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted. Initial police reports had described the incident as a botched robbery. Witnesses say a half dozen grenades also went off along with volleys of gunfire in and around the mall. (AP Photo/Jason Straziuso)

  • An injured person makes a phone call as he is helped on his arrival at the Aga Khan Hospital in Nairobi after an attack at the Westgate Mall, an upscale shopping mall in Nairobi, Kenya Saturday Sept. 21, 2013, where shooting erupted when armed men staged an attack. A witness to the attacks says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted. Initial police reports had described the incident as a botched robbery. Witnesses say a half dozen grenades also went off along with volleys of gunfire in and around the mall. (AP Photo/Jason Straziuso)

  • An armed police officer takes cover during a bout of gunfire outside the Westgate Mall in Nairobi, Kenya, Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Ben Curtis)

  • Armed police take cover behind escalators as smoke fills the air inside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday, killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Jonathan Kalan)

  • A body is seen on the floor, below right, as smoke fills the air inside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday, killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Jonathan Kalan)

  • Civilians who had been hiding inside during the gun battle manage to flee from the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday, killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Jonathan Kalan)

  • Armed police leave after entering the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday, killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Jonathan Kalan)

  • Civilians who had been hiding inside during the gun battle manage to flee from the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday, killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Jonathan Kalan)

  • A woman who had been hiding during the gun battle runs for cover after armed police, seen behind, enter the Westgate Mall in Nairobi, Kenya, Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday, killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Jonathan Kalan)

  • Armed police leave after entering the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday, killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Jonathan Kalan)

  • Armed police crouch down and take position during a gun battle outside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Jonathan Kalan)

  • A woman who had been hiding inside and managed to flee, sits in a state of shock, as an unidentified armed member of the security forces, above, keeps watch outside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Jonathan Kalan)

  • Security helps a woman outside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013, after gunmen threw grenades and opened fire during an attack that left multiple dead and dozens wounded. A witness to the attacks on the upscale shopping mall says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted. (AP Photo/Khalil Senosi)

  • Civilians who had been hiding during the gun battle hold their hands in the air as a precautionary measure before being searched by armed police leading them to safety, inside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday, killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Jonathan Kalan)

  • Civilians who had been hiding inside during gunbattles manage to flee from the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013. Gunmen threw grenades and opened fire Saturday killing at least 22 people in an attack targeting non-Muslims at an upscale mall in Kenya's capital that was hosting a children's day event, a Red Cross official and witnesses said. (AP Photo/Jonathan Kalan)

  • Security helps people outside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013, after gunmen threw grenades and opened fire during an attack that left multiple dead and dozens wounded. A witness to the attacks on the upscale shopping mall says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted. (AP Photo/Khalil Senosi)

  • Armed special force aim their guns at the Westgate Mall in Nairobi, Kenya on Saturday, Sept. 21 2013, after gunmen threw grenades and opened fire during an attack that left multiple dead and dozens wounded. A witness to the attacks on the upscale shopping mall says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted(AP Photo/Khalil Senosi)

  • Security helps a wounded woman outside the Westgate Mall in Nairobi, Kenya Saturday, Sept. 21, 2013, after gunmen threw grenades and opened fire during an attack that left multiple dead and dozens wounded. A witness to the attacks on the upscale shopping mall says that gunmen told Muslims to stand up and leave and that non-Muslims would be targeted. (AP Photo/Khalil Senosi)

  • KENYA-UNREST-ATTACK

    A policeman carries a baby to safety after masked gunmen stormed an upmarket mall and sprayed gunfire on shoppers and staff, killing at least six on September 21, 2013 in Nairobi. The Gunmen have taken at least seven hostages, police and security guards told an AFP reporter at the scene. AFP PHOTO/SIMON MAINA (Photo credit should read SIMON MAINA/AFP/Getty Images)

  • KENYA-UNREST-ATTACK

    A Kenyan woman is helped to safety after masked gunmen stormed an upmarket mall and sprayed gunfire on shoppers and staff, killing at least six on September 21, 2013 in Nairobi. The Gunmen have taken at least seven hostages, police and security guards told an AFP reporter at the scene. AFP PHOTO/SIMON MAINA (Photo credit should read SIMON MAINA/AFP/Getty Images)

  • KENYA-UNREST-ATTACK

    A dead body lies on the ground as armed policemen try enter the Westgate mall after masked gunmen stormed an upmarket mall and sprayed gunfire on shoppers and staff, killing at least six on September 21, 2013 in Nairobi. The Gunmen have taken at least seven hostages, police and security guards told an AFP reporter at the scene. AFP PHOTO/SIMON MAINA (Photo credit should read SIMON MAINA/AFP/Getty Images)

  • KENYA-UNREST-ATTACK

    A policeman carries a baby to safety after masked gunmen stormed an upmarket mall and sprayed gunfire on shoppers and staff, killing at least six on September 21, 2013 in Nairobi. The Gunmen have taken at least seven hostages, police and security guards told an AFP reporter at the scene. AFP PHOTO/SIMON MAINA (Photo credit should read SIMON MAINA/AFP/Getty Images)

  • KENYA-UNREST-ATTACK

    A body of a man lies on the ground as armed policemen try to get entry into the Westgate after masked gunmen stormed an upmarket mall and sprayed gunfire on shoppers and staff, killing at least six on September 21, 2013 in Nairobi. The Gunmen have taken at least seven hostages, police and security guards told an AFP reporter at the scene. AFP PHOTO/SIMON MAINA (Photo credit should read SIMON MAINA/AFP/Getty Images)

  • KENYA-UNREST-ATTACK

    Injured people receive assistance from bypassers after masked gunmen stormed an upmarket mall and sprayed gunfire on shoppers and staff, killing at least thirteen on September 21, 2013 in Nairobi. The Gunmen have taken at least seven hostages, police and security guards told an AFP reporter at the scene. AFP PHOTO/SIMON MAINA (Photo credit should read SIMON MAINA/AFP/Getty Images)

  • KENYA-UNREST-ATTACK

    Injured people sit on the street waiting for assistance after masked gunmen stormed an upmarket mall and sprayed gunfire on shoppers and staff, killing at least thirteen on September 21, 2013 in Nairobi. The Gunmen have taken at least seven hostages, police and security guards told an AFP reporter at the scene. AFP PHOTO/SIMON MAINA (Photo credit should read SIMON MAINA/AFP/Getty Images)

  • KENYA-UNREST-ATTACK

    People run away from an upmarket mall after masked gunmen stormed it and sprayed gunfire on shoppers and staff, killing at least six on September 21, 2013 in Nairobi. The Gunmen have taken at least seven hostages, police and security guards told an AFP reporter at the scene. AFP PHOTO/SIMON MAINA (Photo credit should read SIMON MAINA/AFP/Getty Images)

More from the Press Association:

Kenya has seen a rise in terror attacks and threats in recent years, some of which are believed to be in retaliation for a military crackdown on the Somali-based militant group al-Shabaab, which vowed to retaliate with a large-scale attack on Nairobi.

The attacks often involve gunmen armed with automatic weapons and grenades, and their targets include bars, nightclubs and restaurants in various parts of the country.

There was a suspected al-Shabaab attack which left five dead and three injured at a restaurant in the eastern city of Garissa in January, and in August last year one person was killed and six more were left injured in the Eastleigh area of Nairobi on the eve of a visit by Hillary Clinton, then the United States secretary of state.

Last month 18 US embassies and consulates across the Middle East and Africa were closed after a message between al Qaida officials about plans for a major terror attack was intercepted. British nationals have been told to avoid the Westlands district of Nairobi in the wake of the attack.

A Foreign Office spokesman said: "We are aware of the incident at the Westgate Mall shopping centre, and we are urgently looking into it. "We stand ready to provide consular assistance if there are any British nationals involved." The Foreign Office updated the travel advice on its website to say: "British nationals should avoid the area".