It will take time to arrest protesters who smashed windows and burned cars during the demonstration outside a NATO conference since most of them were covering their faces, Montreal's mayor and police chief both told reporters on Monday.

During a news conference, Mayor Valerie Plante said the demonstrators are known to police. "But with the masks, it requires a little more time, more precision," she said. "We want it to hold up in court as well."

Montreal police have so far arrested three people in connection with the protest, and police Chief Fady Dagher says there will be more arrests.

In an interview with Radio-Canada on Monday, Dagher pointed to a bylaw, repealed in 2019, that banned masking during demonstrations. Police used to be able to intercept masked protesters before they could do any damage, he said, but now they can only intervene "when a person commits a crime."

"These are powers that we don't have anymore," he said. "I work in a legislative framework, and whether you like it or not, that is the framework. I have no choice."

The bylaw, known as P-6, was introduced in 2012 by former Montreal mayor Gerald Tremblay during the height of student protests over a plan to hike university tuition. Aside from banning masks, it also required protesters to provide police with their route ahead of time.

The Quebec Superior Court ruled in 2016 that the ban on masks was unconstitutional, and Plante's government officially scrapped P-6 in 2019. At the time, the mayor said it was the right thing to do to support people's right to protest.

Plante struck a slightly different tone when asked about the bylaw on Monday, saying the court decided it's "not acceptable" to prevent people from covering their faces during protests. "We need to work within those conditions," she said. "That being said, I feel for the police officers ... (who) are facing difficulties when it comes to identifying some people."

Benoit Allard, a spokesperson for Divest for Palestine, one of the groups that organized Friday's demonstration, said peaceful protesters have good reason to cover their faces. "There are lots of threats against people who are demonstrating, especially as we've seen with the Palestinian movement," he said. "First of all, there's repression by the police. We know that the police target activists."

He also said some protesters have lost their jobs after being denounced to their employers.

Anais Bussieres McNicoll, director of the fundamental freedoms program at the Canadian Civil Liberties Association, said protesters have "a very legitimate fear of reprisal" and that people have the right to freedom of expression while maintaining a degree of anonymity.

"I think that it's crucial for people to be able to engage in lawful, peaceful activities ... without the fear of being monitored and surveilled by the state and the police," she said.

It is illegal, however, to wear a mask during a riot. The former federal Conservative government passed a law in 2013 to prevent rioters from concealing their identity, which carries a maximum prison sentence of 10 years. Bussieres McNicoll said the violent demonstrators on Friday could be convicted of that offence if the event is deemed to have been a riot.

Plante and Dagher both defended the police response to Friday's violence, saying the Montreal police have monitored nearly 500 protests since the start of the Israel-Hamas war over one year ago, mostly without incident.

"This is not what is happening in Montreal," Dagher told Radio-Canada on Monday. "This is what happened in one location in Montreal for five minutes."

Allard said he's more concerned about the police response to the protesters than about the damage caused by demonstrators. He said dozens of people were injured by police, and at least four were sent to hospital.

"What we see in the media is a lot of talk about the so-called violence of the protesters, but we're never talking about the violence that we sustained," he said. "The media seems to care only about one specific form of violence, the violence of the people that are resisting oppression."

This report by The Canadian Press was first published Nov. 25, 2024.