Occupy Montreal protesters started tearing down camp Thursday afternoon after the city asked them to vacate Victoria Square on the spot.

Police posted a second round of eviction notices Thursday morning that were more strongly worded than a previous warning issued the previous night.

Thursday's notice asked occupiers to vacate "immediately."

A city spokesman says Montreal wants the campers to leave on their own, but he adds that necessary measures will be taken if required.

"We have indicated that the period of tolerance towards the protesters at the campground is over and that we will apply the city's existing bylaws," Gonzalo Nunez said on Thursday. "We're still working on convincing the protesters to act on a voluntary basis."

The original notices, handed out Wednesday, asked protesters at Victoria Square to take down their tents and respect the square's midnight to 6 a.m. curfew bylaw, but issued no specific deadline.

Protester Alain Berger said the notices have created a great deal of stress among the occupiers.

"Many people here were panicked thinking that they had to dismount the camp in the snow, that they only had a few hours," said Berger.

A Montreal police officer posts an eviction notice at Victoria Square Thursday morning. CBC/Peter Akman

The Montreal protest, which first set up camp on Oct. 15, remains the last-standing of three biggest Canadian centres where the Occupy movement took root.

The tents have already come down in Toronto but protesters, joined by hundreds of unionized workers, held a march Thursday. They marched through the city's financial district, ending with a short rally outside city hall at Nathan Phillips Square.

In Vancouver, police moved in earlier this week to dismantle a second Occupy site that sprang up after the initial site at an art gallery was deemed illegal and ordered removed.

In Montreal, protesters enjoyed Mayor Gérald Tremblay's support until a few days ago.

But reports of drug use and scuffles at Montreal's protest site – which coincided with the dismantling of other cities' camps – appeared to trigger an instant policy shift.

The city says protesters have had trouble co-habitating with some of the homeless, while other campers have had health issues and there have also been fire hazards.

The structures also have been covered in snow this week during the city's first winter storm of the season.

A big demonstration has also been planned at the Montreal site on Saturday.

With files from the Canadian Press