RCMP Commissioner Bob Paulson said authorities had not been watching the gunman in advance of his deadly attack on a soldier.

At a news conference on Thursday, Paulson said that Zehaf-Bibeau had recently applied for a passport, but that he wasn't a "high-risk" traveler.

Authorities now believe he intended to go to Syria.

Security remains tight across the country in the aftermath of Wednesday's attack - the nation's parliament remains under close surveillance by police and it is closed to the public.

One Member of Parliament (MP) Tony Clement told reporters that as he was trying to flee the shooting, he inadvertently walked into the shooting zone.

"I thought where we were was going to be the murder zone and so, for me to get out of there made the most sense, although we ran right into the fusillade," Clement said.

He recounted how he later hid in an unlocked office waiting to be rescued.

It's the second attack on a Canadian soldier this week - on Monday a "Muslim convert" killed a Canadian soldier in a hit and run incident in Quebec.

Canadian police say they have found no connection between the two attacks.

Concerns are being raised, however, that the country is being targeted for joining the US-led air campaign against the extremist ISIS group in Iraq and Syria.         

Abubakir Abdelkareem, 29, who often visited the Ottawa Mission, a homeless shelter downtown, said he met Zehaf-Bibeau there.

He said Zehaf-Bibeau told him he had a drug problem in Vancouver but had been clean for three months.

Abdelkareem told The Associated Press that Zehaf-Bibeau wanted his passport to fly to Libya because he thought he could avoid drugs there.

On Thursday Prime Minister Stephen Harper visited the National War Memorial where army reservist, Corporal Nathan Cirillo was killed to lay a wreath.