OTTAWA, Ontario (AP) — Police in Canada’s capital have called in reinforcements as a planned anti-vaccine mandate protest began to swell in numbers.

Several thousand people are expected in Ottawa as part of group demanding an end to vaccine mandates and COVID-19 restrictions. Some of the group’s leaders are calling for a peaceful event, but statements from some associated with the group have included threats of violence.

Ottawa police are working with national security agencies to identify any potential threats to public safety, Chief Peter Sloly said during a press briefing on Friday.

“Even during the course of this conference call we’ve had new intelligence coming in regards to local threats,” he said.

A top Parliament security official has warned lawmakers to lock their doors amid reports their private homes may be targeted.

Trucks and cars began rolling into downtown Ottawa midday Friday, as a planned anti-vaccine mandate protest grew. They have set up in the streets around Parliament Hill for the weekend — and possibly longer.

Trucks and cars lined the north side of the main street outside, far past the Parliament buildings. Thus far the atmosphere has been generally party-like with some setting up barbecues on the sidewalk, and many honking horns, playing instruments and blaring music.

They are, in part, protesting a new rule that took effect Jan. 15 requiring truckers entering Canada be fully immunized against the coronavirus. The United States has imposed the same requirement on truckers entering that country.

While the protest has largely been billed as being against a new vaccine mandate for commercial truck drivers at the border, its origins go back long before that policy was conceived.

The memorandum of understanding being pushed by organizer calls for Trudeau and all provincial governments to eliminate all COVID-19 restrictions and vaccine mandates. The document fails to mention truckers at all.

Robyn May, a business owner from Long Point, Ontario was there with her husband in hockey jerseys, toting anti-Trudeau signs.

“We are not a free country,” May said, adding government mandates forced her business to close at times during the pandemic.

When asked how long she thinks the protest will last, she said she plans to stay until “Justin Trudeau is no longer our prime minister.”

The police chief said there are concerns about “parallel demonstrations,” as some with extreme, far-right and white supremacist views have latched onto the protest as the convoy has crossed the country.

The Canadian government ended the truckers’ exemption to the vaccine mandate, meaning Canadian truck drivers need to be fully vaccinated if they want to avoid a two-week quarantine and pre-arrival molecular test for COVID-19 before crossing into Canada.

Unvaccinated or partially vaccinated foreign national truck drivers who do not have a right to re-enter are turned away at the border and directed back to the United States. The U.S. now also requires Canadian truckers to provide proof of vaccination to enter that country.

The Canadian Trucking Alliance has disavowed the protest and said more than 85% of truckers are vaccinated.