Ford and Toyota on Wednesday said they were halting some production as anti-coronavirus mandate protesters blocked United States-Canada border crossings, which 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, amid decreasing cases of the highly infectious Omicron variant in some places.
Some carmakers have now been affected by the disruption near Detroit, the historic heart of the US automotive sector. But there were other factors too, such as severe weather and a shortage of semiconductor chips.
Toyota, the top US seller, said it is not expected to produce vehicles at its Ontario sites for the rest of the week.
Output has been halted at a Ford engine plant and Chrysler-maker Stellantis has had its production disrupted.
Another border crossing in the province of Alberta has been closed in both directions since late Tuesday.
More than two-thirds of the 650 billion Canadian dollars ($511bn) in goods traded annually between Canada and the US is transported by road.
The “Freedom Convoy” occupying downtown Ottawa was started by protesters opposing a vaccinate-or-quarantine mandate for cross-border truckers and was mirrored in the US. Protesters in Canada are now also airing grievances about a carbon tax and other legislation.