A midday shooting in the Canadian city of Montreal left a police officer, a civilian and the armed assailant dead on Monday.

Axar.az reports, citing BBC, the unidentified male suspect, who is believed to have acted alone, was shot and killed right away, the city's police chief said. One other police officer was severely injured and was reportedly in stable condition.

The attack unfolded in a diverse part of the city, Côte-des-Neiges. A witness saw a "gun sticking out of a window", heard shots and called police, said investigators.

Quebec's security minister said the motive was unclear. It was the first time a Montreal police officer had been killed in the line of duty in nearly a quarter of a century.

Becoming emotional during a press conference, Montreal Police Chief Fady Dagher told reporters: "It's a nightmare."

The police department later named the officer killed as Mohamed Lamine Benredouane, 34, who had been part of the force since 2021.

The civilian killed in the attack was Michael Moshe Mizrahi, "a beloved member of Montreal's Jewish community", said the Centre for Israel and Jewish Affairs.

Ian Lafrenière, Quebec's domestic security minister, said earlier: "For now, we don't really know what the motive of this individual was."