Ford and Toyota both halted some production as anti-coronavirus mandate protesters blocked the U.S-Canada border crossings that have prompted warnings from Washington and Ottawa of economic damage.

Many pandemic-weary Western countries will soon mark two years of restrictions as copycat protests spread to Australia, New Zealand and France now that the highly infectious omicron variant begins to ease in some places.

The convoy-style protest by people mainly in pickup trucks has been blocking the Ambassador Bridge between Detroit and Windsor, Ontario. Traffic was prevented from entering Canada, while the U.S.-bound traffic was still moving.

The bridge is vital as it carries 25% of all trade between the two countries, and Canadian authorities expressed increasing worry about the economic effects.

Horn-blaring protests have been causing gridlock in the capital Ottawa since late January and from Monday night, truckers shut inbound Canada traffic at the Ambassador Bridge, a supply route for Detroit's carmakers and agricultural products.

A number of carmakers have now been affected by the disruption near Detroit, the historic heart of the U.S. automotive sector, but there were other factors too such as severe weather and a shortage of semiconductor chips contributing to the suspension of production.

Ford said late Wednesday that parts shortages forced it to shut down its engine plant in Windsor and to run an assembly plant in Oakville, Ontario, on a reduced schedule.

"This interruption on the Detroit-Windsor bridge hurts customers, auto workers, suppliers, communities and companies on both sides of the border," Ford said in a statement. "We hope this situation is resolved quickly because it could have a widespread impact on all automakers in the U.S. and Canada."

Shortages due to the blockade also forced General Motors to cancel the second shift of the day at its midsize-SUV factory near Lansing, Michigan. Spokesperson Dan Flores said it was expected to restart yesterday and no additional impact was expected for the time being.

Toyota, the top U.S. seller, said the company will not be able to manufacture anything at three Canadian plants for the rest of this week due to a parts shortage. A statement attributed the problem to supply chain, weather and pandemic-related challenges, but the shutdowns came just days after the blockade began Monday.

"Our teams are working diligently to minimize the impact on production," the company said, adding that it doesn’t expect any layoffs at this time.

Stellantis, formerly Fiat Chrysler, reported normal operations, though the company had to cut shifts short the previous day at its Windsor minivan plant.

Another border crossing, in Alberta province, has been closed in both directions since late on Tuesday.

More than two-thirds of the CA$650 billion ($511 billion) in goods traded annually between Canada and the U.S. is transported by road.

Alberta, Saskatchewan, Quebec, Prince Edward Island and Nova Scotia announced plans this week to roll back some or all of their precautions. Alberta, Canada's most conservative province, dropped its vaccine passport immediately and plans to get rid of mask requirements at the end of the month.

Alberta opposition leader Rachel Notley accused the province's premier, Jason Kenney, of allowing an "illegal blockade to dictate public health measures."

Despite Alberta’s plans to scrap its measures, the protest there continued.

"We’ve got guys here – they’ve lost everything due to these mandates, and they’re not giving up, and they’re willing to stand their ground and keep going until this is done," said protester John Vanreeuwyk, a feedlot operator from Coaldale, Alberta.

"Until (Justin) Trudeau moves," he said, "we don’t move."

Starting as a "Freedom Convoy" occupying downtown Ottawa opposing a vaccinate-or-quarantine mandate for cross-border truckers mirrored by the U.S. government, protesters have also aired grievances about a carbon tax and other legislation.

"I think it's important for everyone in Canada and the United States to understand what the impact of this blockage is – potential impact – on workers, on the supply chain, and that is where we're most focused," White House Spokesperson Jen Psaki said on Wednesday.

"We're also looking to track potential disruptions to U.S. agricultural exports from Michigan into Canada."

Washington is working with authorities across the border to reroute traffic to the Blue Water Bridge, which links Port Huron in Michigan with Sarnia in Ontario, amid worries that protests could turn violent, she told reporters.

Bank of Canada Governor Tiff Macklem called for a swift resolution. "If there were to be prolonged blockages at key entry points into Canada that could start to have a measurable impact on economic activity," he said.

"We've already got a strained global supply chain. We don't need this."

Protests spread

The protests were disrupting jobs too and "must end before further damage occurs," Canada's Emergency Preparedness Minister, Bill Blair, told reporters.

Protesters say they are peaceful, but some Ottawa residents have said they were attacked and harassed. In Toronto, streets were being blocked.

"We continue to know that science and public health rules and guidance is the best way to this pandemic is the way we're going to get to the other side," said Canadian Prime Minister Justin Trudeau.

Trudeau stood firm against easing Canada's COVID-19 restrictions in the face of mounting pressure during recent weeks by protests against the restrictions and the prime minister himself.

The issue has caused a sharp split between the ruling Liberals and the opposition Conservatives, many of whom have expressed open support for the protesters in Ottawa and accuse Trudeau of using the issue of the mandate for political purposes.

In the U.S., prosecutors in Missouri and Texas will probe crowdfunding service GoFundMe over the decision to take down a page for a campaign in support of the drivers after some Republicans vowed to investigate.

Downtown Ottawa residents criticized police for their initially permissive attitude toward the blockade, but authorities began trying to take back control Sunday night with the seizure of thousands of liters of fuel and the removal of an oil tanker truck.

Police have asked for reinforcements – both officers and people with legal expertise in insurance and licensing – suggesting intentions to pursue enforcement through commercial vehicle licenses.

But as the authorities attempt to quell demonstrations in one area, they pop up elsewhere.

"Even as we have made some headway in Ottawa, we've seen an illegal blockade emerge in Windsor," said Public Safety Minister Marco Mendicino.

About 90% of truckers in Canada are vaccinated, and trucker associations and many big-rig operators have denounced the protests. The U.S. has the same vaccination rule for truckers entering the country, so it would make little difference if Trudeau lifted the restriction.

Protesters have also been blocking the border crossing at Coutts, Alberta, for a week and a half, with about 50 trucks remaining there Wednesday. And more than 400 trucks have paralyzed downtown Ottawa, Canada’s capital, in a protest that began late last month.

While protesters have been calling for Trudeau’s removal, most of the restrictive measures around the country have been put in place by provincial governments. Those include requirements that people show proof-of-vaccination "passports" to enter restaurants, gyms, movie theaters and sporting events.

At a news conference in Ottawa that excluded mainstream news organizations, Benjamin Dichter, one of the protest organizers, said: "I think the government and the media are drastically underestimating the resolve and patience of truckers."

"Drop the mandates. Drop the passports," he said.

Pandemic restrictions have been far stricter in Canada than in the U.S., but Canadians have largely supported them. Canada's COVID-19 death rate is one-third that of the U.S.

Interim Conservative leader Candice Bergen said in Parliament that countries worldwide are lifting restrictions and noted that Canadian provinces are, too. She accused Trudeau of wanting to live in a "permanent pandemic."

Ontario, Canada’s largest province with almost 40% of the country's population, is sticking to what it calls a "very cautious" stance toward the pandemic, and the deputy premier said it has no plans to drop vaccine passports or mask requirements.