It is believed the terrorist gunman in Canada was a lone wolf and acted alone.
Michael Zehaf-Bibeau, 32, was shot dead after killing a soldier and going on a shooting rampage in the Canadian parliament on Thursday.
Officials said he had a criminal record and had recently applied for a passport, planning to travel to Syria after undergoing a "radicalisation process."
Police also said he was a Canadian who may also have held Libyan citizenship and had no apparent links to another Canadian who killed a soldier in Quebec earlier in the week.
Mr Zehaf-Bibeau fatally shot a soldier at the National War Memorial in the capital Ottawa, before racing through the parliament building where he was shot dead by parliament's sergeant-at-arms.
Canada's parliament has returned to work after the shootings.
It opened with applause for the sergeant and a moment's silence.
It was the second attack on Canada's military in three days.
Standing to address the MPs to warm applause, Prime Minister Stephen Harper's first words were: "I know we will always stand together."
The objective of the attacks was to instill fear and panic in Canada, he said.
But he vowed to expedite security measures to strengthen powers of surveillance and detention.
"We will be vigilant, but we will not run scared. We will be prudent, but we will not panic.
"And as for the business of government, well here we are, in our seats, in our chamber, in the very heart of our democracy and our work goes on."
On Monday, another soldier was killed in a hit-and-run in the province of Quebec. Mr Harper described the perpetrator, who was shot dead, as an "ISIL-inspired terrorist".
Canada recently announced plans to join the US-led campaign of air strikes against IS militants in Iraq but no link to IS or the new military campaign has been confirmed by police investigating the latest attack.
The gunman was reportedly a Muslim convert named Michael Zehaf-Bibeau, who was on a Canadian watchlist.
His mother Susan Bibeau said she was crying for the victims and was at a loss about what to say to those hurt in the attack.
"Can you ever explain something like this?'' she said. "We are sorry."
The heart of Canada's capital city had been in lockdown after the attack as police combed the streets looking for another gunman.
But police said that they believed there was only one assailant.
The attack began on Wednesday morning (local time), as two soldiers guarding the memorial came under fire from a man carrying a rifle.
One soldier, Cpl Nathan Cirillo, died of his injuries. Three other people were treated in hospital and released by evening.
Minutes after the attack at the memorial, dozens of shots were fired inside the parliament building.
The gunman was shot dead by Sergeant-at-Arms Kevin Vickers, 58.
MPs applauded Mr Vickers for several minutes on Thursday, banging on their desks in support and appreciation of his service and actions a day prior.
Zehaf-Bibeau, 32, had apparently been designated a high-risk traveller and had his passport taken away because of suspected jihadist sympathies.
A Twitter user who posted an image purporting to show Zehaf-Bibeau said it had come from an IS-linked account.