Police in Canada’s capital city have begun blocking off the downtown core with barriers and fences and setting up checkpoints in a move against protesters who have occupied the streets for nearly three weeks.

“We’ve been bolstering our resources, developing clear plans, and preparing to take action. The action is imminent,” Ottawa Police Chief Steve Bell said at a news conference. He said a large area of the city’s core would become a secure zone, with 100 police checkpoints restricting access to local residents, workers and others who have a legal reason for being there.

To the protesters, Bell said: “Get in your truck. We will navigate safe passage for you to leave our city streets. We want this demonstration to end peacefully.”

For a second consecutive day, Ottawa police handed out pamphlets warning of criminal charges and vehicle seizures for anyone who doesn’t leave the protest zone. The area has been declared a prohibited public assembly under emergency legislation invoked by Prime Minister Justin Trudeau on Monday. 

Hundreds of protesters were still refusing to go, blocking the roadway in front of Canada’s parliament and on adjacent streets. The first demonstrators arrived on Jan. 28; they’re calling for an end to vaccine mandates and other COVID-19 restrictions. 

The protests have grown into the thousands on weekends, so police are particularly focused on deterring people from deciding to join the crowds. It’s a holiday long weekend in Canada. 

“This weekend will look very different from the past three weekends,” Bell said. 

Trudeau kicked off formal debate on his use of emergency powers Thursday with a speech in the House of Commons, saying the situation “could not be dealt with under any other law in Canada.”

He said the blockades in Ottawa and at border crossings between Canada and the U.S. are “a threat to our economy and relationship with trading partners. They’re threats to supply chains and the availability of essential goods like food and medicine. They’re a threat to public safety.”

But the opposition Conservatives accused Trudeau of resorting too quickly to emergency powers and of freezing bank accounts of protesters without evidence of extremist activity.