In Quebec City on Tuesday, Legault said he has told Montreal Mayor Valerie Plante that it's "urgent" those responsible be arrested in the coming days.

"There must be a very clear message sent to these thugs that they will be punished, they will be arrested, there will be consequences for what they have done," he told reporters.

Asked if he has confidence in the Montreal police, Legault said he's expecting far more than the three arrests announced to date. "So until proven otherwise, we have confidence in the (police), but I expect there to be action in the coming days," he said.

Earlier Tuesday, Montreal police Chief Fady Dagher told The Canadian Press that police are working to arrest other violent protesters. But he said most of the participants wore masks, which makes it harder to identify them.

Dagher said those responsible are part of an "extreme-left group," known to police for the last 20 years, that had "nothing to do" with pro-Palestinian protesters who attended the demonstration on Friday. He would not name the group, however.

Protest organizers bear limited responsibility for the violence that unfolded during the demonstration, he said, adding that it's a major challenge to prevent people bent on violence from infiltrating protests.

"It's very difficult for them to anticipate and to block them from demonstrating, because demonstration is a right in Canada. So any human being has the right to demonstrate," Dagher said. "I think it's an impossible situation for the organization to make sure they're not inside the crowd."

The protest, which attracted about 800 people, was organized by the group Divest for Palestine and a Montreal anti-capitalist group, known as CLAC, which opposes NATO in part because of its support for Israel.

In an anonymous statement posted online, a group calling itself the "Black Bloc" has claimed responsibility for the violence, which it says was part of its fight against capitalism. "There is no more time to stay calm and ask nicely," the statement reads. "Resistance is legitimate, the state and the police can no longer have a monopoly on violence -- especially if it is the only language they will hear."

Protesters on Friday smashed windows of the convention centre where the NATO meeting was being held, and those of nearby businesses. Two cars were lit on fire, though media reports have suggested that one car may have been damaged by a tear gas canister. Dagher said police are looking into it. The police chief also said demonstrators filled fire extinguishers with paint that they sprayed at riot police to block their vision.

He lamented that people who vandalize property during protests rarely get more than a fine, a punishment he believes is too light.

"After that, two weeks later, one month later, we see them again on the street," he said.

Benoit Allard, a spokesperson for Divest for Palestine, said he wouldn't speculate on who was responsible for Friday's violence, but said he understood what led people to act out.

"What I felt ... was an enormous anger from people who have been mobilizing for over a year," he said during an interview Monday. "What do you do ... when all the peaceful ways of protesting have been tested, used, and you're not heard?"

Allard said his group had organized another protest a day earlier against NATO member states sending weapons to Israel. "It was a peaceful protest. But nobody talked about it," he said. "So when nobody cares about the peaceful protests, what message does it send?"

The Montreal police are also facing criticism for their treatment of a local rabbi who says he was asked to "leave the area" of a pro-Palestinian protest on Sunday. Adam Scheier says he was in downtown Montreal to buy a drink at Second Cup, in support of the company's decision to cut ties with a franchisee who was filmed last week making a Nazi salute and antisemitic remarks during a protest in the city.

Scheier says he was filming the Sunday protest when police asked him and his family to leave. "The only thing I am guilty of is shopping in downtown Montreal ... while wearing a kippah," he wrote on Facebook, referring to the brimless cap worn by Jewish men.

"The policeman explained to me that he was fearful of a 'fire starting between the two sides.' Apparently, my presence is deemed a sufficient provocation for removal, while their hateful chants are allowed to continue."

Dagher said he doesn't know all the details of the incident, but that police have a responsibility to protect anyone who might be vulnerable. "If my cop asked him to move, it's because they saw the violence was escalating and they want to find a solution to avoid any violence," he said, adding that one of his team will meet with Scheier.

"It's not because I want to deprive him of his freedom at all."

Dagher said there have been more than 400 demonstrations in Montreal since the Oct. 7 Hamas attack on Israel, and that the vast majority of them have been peaceful.

"Everybody thinks that Montreal is on fire," he said. "It happened one night, one moment, at one place. ... I just want people to remember that Montreal is an extremely safe city."

This report by The Canadian Press was first published Nov. 26, 2024.