A man dressed in medieval clothes killed at least two people with a sword in Quebec, Canada police authority said.
Five others were wounded in the Halloween night attack after a man in his mid-20s was arrested shortly before 01:00 (06:00 GMT) on Sunday.
Police advised residents to stay inside with doors locked while an investigation was underway.
The attack took place in the historic Old Quebec neighbourhood.
Prime Minister Justin Trudeau said on Twitter: “My heart breaks for the loved ones of the two killed in last night’s horrific attack in Quebec City.
“I’m also wishing a full recovery to the injured. We’re keeping you in our thoughts and will be there for all of you.”
He also thanked first responders for their critical work.
Police tweeted that there was no immediate indication “that the suspect may have acted for motives other than personal ones”.
The suspect’s identity has not been made public.
First reports of the incident near the French-speaking city’s national assembly came through shortly before 22:30 local time on Saturday.
The suspect was arrested near the Espace 400e business park.
Quebec’s Le Soleil newspaper reported that he was lying on the ground, barefoot and hypothermic when he was arrested. He surrendered to police without any resistance, it said.
Following his arrest, the suspect was taken to hospital for “evaluation”.
The five wounded are also being treated in hospital, with varying levels of injury, according to police.
Police have not released details of the victims’ identities or ages.
Reporters at the scene have tweeted photos of a police command post outside Quebec’s Parliament Building.
At a news conference on Sunday, Quebec City police spokesman Étienne Doyon offered “sincerest condolences to the loved ones and families of the people who died”.
Source: BBC News