Police in Canada said they stopped a convoy of transport trucks they suspect planned to cause havoc in Windsor, Ontario, once again.

Protesters, who have issues with vaccine and mask mandates, and others who want Prime Minister Justin Trudeau to step down, blocked access to the Ambassador Bridge for six days last week. The span is a key trade link between Canada and the U.S.

The demonstrations cost the North American auto industry hundreds of millions of dollars in lost production and wages.

Windsor Police Chief Pam Mizuno said at a news conference Wednesday that six or seven westbound trucks on Highway 401 originated in Ottawa and were stopped by police Tuesday, about 155 miles from Windsor.

“It is suspected this convoy was headed to Windsor,” Mizuno said.

She didn’t say whether the Ambassador Bridge was the convoy’s ultimate destination. 

Windsor Mayor Drew Dilkens said at the news conference that $400 million worth of trade crosses the bridge both ways to and from Detroit each day. The bridge sees 10,000 trucks cross it every day and it handles 30 percent of all Canada-U.S. trade, he said.

“We cannot and we will not allow another illegal occupation,” Dilkens said.

Mizuno said commercial and essential traffic is flowing smoothly now and that security measures are “assessed on a continual basis.”

“There is a broader plan in place to protect our border,” Mizuno said. “There remains a risk that compels action from all levels of government.”