OTTAWA, Ontario — Two deadly attacks in three days against members of the military stunned Canadians and raised fears their country was being targeted for reprisals for joining the U.S.-led air campaign against an extremist Islamic group in Iraq and Syria.

“We will not be intimidated. Canada will never be intimidated,” Prime Minister Stephen Harper vowed in a nationally televised address hours after a masked gunman killed a soldier standing guard at Ottawa’s war memorial shortly before 10 a.m. on Wednesday. The suspect then stormed Parliament in a dramatic attack that was stopped cold when he was shot to death by the ceremonial sergeant-at-arms.

Harper 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.

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.