Forensic police officers work near the National War Memorial in Ottawa, Canada, on Wednesday. A gunman opened fire at the National War Memorial, killing a soldier before entering Parliament Hill and firing several shots in the building. Police shot dead the gunman and said an investigation was underway. Photo: AFP

Canadian Prime Minister Stephen Harper pledged more surveillance and detention powers for security forces in Canada on Thursday after a gunman killed a soldier and rampaged through parliament before being shot dead.

Addressing the House of Commons just meters away from where the gunman, a reported convert to Islam, was shot dead on Wednesday, Harper said lawmakers would expedite new powers to counter the threat of radicals.

"The objective of these attacks was to instill fear and panic in our country," Harper said. "Canadians will not be intimidated. We will be vigilant, but we will not run scared. We will be prudent but we will not panic."

Harper pledged to speed up a plan already under way to bolster Canadian laws and police powers in the areas of "surveillance, detention and arrest."

The killing of the Canadian soldier was the second this week with a possible link to Islamist militants. A convert to Islam on Monday ran over two Canadian soldiers with his car, killing one, near Montreal, before being shot dead by police.

Both attacks took place after Canada announced this month it would send six jets to take part in air strikes against Islamic State fighters.

Defense Minister Rob Nicholson said Canada's deployment to Iraq would go on unimpeded.

While parliament resumed, tensions in Canada's capital remained high.

Police arrested a man at gunpoint just steps from the prime minister as Harper and his wife were laying a wreath at the National War Memorial to commemorate the killing of the soldier, Nathan Cirillo, 24.

"He crossed the tape. We told him not to. He didn't listen," said a police officer at the scene.

The two attacks in quick succession could push the Canadian government to pause and rethink before introducing a planned bill to change the Canadian Security Intelligence Service Act, said Wesley Wark, a professor at the University of Ottawa, who is an expert on national security and intelligence issues.

The bill to boost the powers of Canada's main spy agency, the Canadian Security Intelligence Service, was slated to be introduced in parliament this week.

"What the government is now confronting is a choice with going forward on whatever its original, probably small-scale changes might have been, or sitting back and thinking about whether there is something more that needs to be done," he said.

Canadian police were investigating a man named Michael Zehaf-Bibeau as a suspect in Wednesday's attack, said a source familiar with the matter.

Court documents show he previously faced a robbery charge in Vancouver and multiple drug-related charges in Montreal.

US officials said they had been advised the dead gunman in Wednesday's shootings was also a Canadian convert to Islam.