"We will not be intimidated. Canada will never be intimidated," Canada's Prime Minister has vowed in an emotional national address just hours after a masked gunman killed a soldier standing guard at Ottawa's war memorial.
In his first address to the nation since the brutal attack, Stephen Harper condemned it as a " brutal attack" and said the country would continue to work with allies in the fight against extremist organisations.
He called it the country's second terrorist attack in three days. A man Harper described as an "ISIL-inspired terrorist" on Monday ran over two soldiers in a parking lot in Quebec, killing one and injuring another before being shot to death by police. Like the suspect from Wednesday's shooting in Ottawa, he was a recent convert to Islam.
Two deadly attacks in three days against members of the military have stunned Canadians and raised fears their country was being targeted for reprisals for joining the US -led air campaign against Islamic State militants in Iraq and Syria.
Zehaf-Bibeau, 32, was raised in Quebec, according to CTV News, and was a Canadian convert to Islam, Reuters said.
It was unclear whether other gunmen remained at large, with police describing the incident as an "ongoing" operation with no-one currently in custody.
Investigators offered little information about the gunman in Ottawa, identified as 32-year-old petty criminal Michael Zehaf-Bibeau. But Harper said: "In the days to come we will learn about the terrorist and any accomplices he may have had."
Witnesses said the soldier posted at the National War Memorial, identified as Cpl Nathan Cirillo, was gunned down at point-blank range by a man carrying a rifle and dressed all in black, his face half-covered with a scarf. The gunman appeared to raise his arms in triumph, then entered Parliament, a few hundred yards away, where dozens of shots soon rang out, according to witnesses.
On Sunday, we asked a very handsome guard for a picture with my friend visiting from Cali - RIP Nathan Cirillo pic.twitter.com/q80EZ6nwmo— Megan Underwood (@megunder) October 22, 2014
People fled the complex by scrambling down scaffolding erected for renovations, while others took cover inside as police with rifles and body armour took up positions outside and cordoned off the normally bustling streets around Parliament.
This is the moment that politicians and reporters cowered as a hail of gunshots echoed through Canada's parliament building, one of a number of incidents that took place across the country's capital.
On Twitter, Canada's justice minister and other government officials credited 58-year-old sergeant-at-arms Kevin Vickers with shooting the attacker just outside the MPs' caucus rooms. Vickers serves a largely ceremonial role at the House of Commons, carrying a scepter and wearing rich green robes, white gloves and a tall imperial hat.
Vickers, a 29-year veteran of the RCMP, was praised by politicians, journalists and the public for saving lives. He told CBC Wednesday afternoon that he is safe and alright.
To all in Ottawa, stay safe & strong. Thank God for Sgt at Arms Kevin Vickers & our Cdn security forces. True heroes #cndpoli— Peter MacKay (@MinPeterMacKay) October 22, 2014
Heroic actions by Sgt. at Arms Kevin Vickers today. He saved lives.— Mercedes Stephenson (@CTVMercedes) October 22, 2014
I am safe & profoundly grateful to Sgt at Arms Kevin Vickers & our security forces for selfless act of keeping us safe— Julian Fantino (@JulianFantino) October 22, 2014
So sad for the family of the fallen soldier. So proud of Kevin Vickers. So mad about it all. So worried about what this will mean.— Martha Hall Findlay (@MHallFindlay) October 22, 2014
Speak softly and carry a big stick. Kevin Vickers is a hero. pic.twitter.com/LNxBLnBAtE— Stephen Taylor (@stephen_taylor) October 22, 2014
Remind me to hug Kevin Vickers next time I see him.— kady o'malley (@kady) October 22, 2014
At least three people were treated for minor injuries.
David Cameron also responded last night to the events on Twitter.
I'm appalled by today's attack in Ottawa. I offer my full support to @pmharper and the Canadian people as they deal with this incident.— David Cameron (@David_Cameron) October 22, 2014
In Washington, President Barack Obama condemned the shootings as "outrageous" and said: "We have to remain vigilant." The US Embassy in Ottawa was locked down as a precaution, and security was tightened at the Tomb of the Unknown Soldier at Arlington National Cemetery just outside Washington.
Harper vowed that the attacks will "lead us to strengthen our resolve and redouble our efforts" to keep the country safe and work with Canada's allies to fight terrorists.
Court records that appear to be the gunman's show that he had a long rap sheet, with a string of convictions for assault, robbery, drug and weapons offences, and other crimes.
Tony Zobl said he witnessed the Canadian soldier being gunned down from his fourth-floor window directly above the National War Memorial, describing how "the honour guard dropped to the ground, and the shooter kind of raised his arms in triumph holding the rifle."
A Facebook page was set up named Rest In Peace Cpl Nathan Cirillo, which has already been looked at by thousands.
One message, from Bob Rodkin, read: "RIP Nathan. Thank you for your service and the ultimate sacrifice. So tragic, so unnecessary. My prayers go out for you and to your family, friends and colleagues."
Another message, from Olivia Marie, said: "RIP Nathan! Thank you for defending our country, your son is so proud of you. I miss you."
Just minutes before being gunned down Wednesday morning, Cpl. Nathan Cirillo stood stoically in front of the National War Memorial.
The moment was captured by a young man from Winnipeg on a tour of the monument who posted the photo to Twitter.
The caption reads: "Ok so we were on a tour at that war monument in Ottawa a few minutes ago, a few seconds later there was a shooting.."
The photo was taken at 9:41 a.m., HuffPost Canada was told by the poster. Just 12 minutes later, at 9:53 am, journalist Peter Henderson sent out what is thought to be the first tweet about the shooting.
Gunfire at the war memorial in downtown #ottawa— Peter Henderson (@Henderburn) October 22, 2014
The attack came two days after a recent convert to Islam killed the Canadian soldier and injured another with his car in a parking lot in the Quebec city of Saint-Jean-Sur-Richelieu. The killer had been on the radar of federal investigators, who feared he had jihadist ambitions and seized his passport when he tried to travel to Turkey.
Canada had raised its domestic terror threat level from low to medium Tuesday because of what it called "an increase in general chatter from radical Islamist organisations." As recently as Tuesday, Canada sent eight fighter jets to the Mideast to join the battle against Islamic State.
An audio recording released in September encouraged Islamic State supporters to kill Canadians, the Toronto Star reported.
The 42-minute propaganda recording released in Arabic by the group’s media arm, Al-Furqan, urged IS followers to kill any "disbelievers,” whether they are "civilians or part of the military."
"If you can kill a disbelieving American or European – especially the spiteful and filthy French – or an Australian or a Canadian, or any other disbeliever from the disbelievers waging war, including the citizens of the countries that entered into a coalition against the Islamic State … kill him in any manner or way however it may be," it stated.
A transcript, distributed on social media, also seemed to accuse countries like Canada and Australia of meddling in affairs that are none of their business, AP reported.
“What threat do you pose to the distant place of Australia for it to send its legions towards you? What does Canada have anything to do with you?”
More than 130 Canadians are believed to be fighting with extremist groups abroad, CTV news reported at the time.