A French-Canadian university student, the sole suspect in a shooting at a Quebec City mosque, has been charged with the premeditated murder of six people.
Prime Minister Justin Trudeau has called it "a terrorist attack".
Court documents identified the gunman in the attack on Sunday evening prayers as Alexandre Bissonnette. He was also charged with five counts of attempted murder, according to court papers.
Among the six men killed were a butcher, a university professor, a pharmacist and an accountant, according to police and Canadian media.
Police declined to discuss possible motives for the shooting at the Centre Culturel Islamique de Quebec.
"They consider this a lone wolf situation," the source said.
Trudeau, who has made a point of welcoming refugees and immigrants from Muslim-majority countries, told parliament in Ottawa: "Make no mistake, this was a terrorist attack."
He added a personal message to Canada's 1 million Muslims: "Know that we value you. You enrich our shared country in immeasurable ways. It is your home. Last night's horrible crime against the Muslim community was an act of terror committed against Canada and against all Canadians.
"We will grieve with you. We will defend you. We will love you. And we will stand with you."
Sombre parliamentarians observed a moment of silence. Trudeau was scheduled to visit Quebec City later on Tuesday (NZ time).
The attack was out of character for Quebec City, a city of just over 500,000 which reported just two murders in all of 2015. Mass shootings are rare in Canada, where gun control laws are stricter than in the United States.
In addition to the six killed, five people were critically injured and 12 were treated for minor injuries, a spokeswoman for the Quebec City University Hospital said.