Production by Japanese automakers has been affected by the closure of a key bridge straddling the United States and Canada due to trucker protests in Canada against COVID-19 vaccine mandates and other restrictions.

The Ambassador Bridge, connecting Detroit and Windsor, Ontario, has been closed since Monday amid the protests, disrupting the transportation of automobile parts and other goods.

The development is a further blow to automakers, which have already been forced to adjust production because of semiconductor shortages.

Officials of Toyota Motor Corp. said Thursday that production at its plants in Ontario and Kentucky have been affected. The impact is expected to continue to be felt over the weekend, with an official saying that the company will continue to adjust production as needed.

Honda Motor Co. suspended one of the production lines at its plant in Alliston, Ontario, on Wednesday night. It was brought back online Thursday, but part of the plant will be suspended again on Friday.

U.S. auto giants General Motors Co. and Ford Motor Co., and U.S.-European group Stellantis have also been forced to adjust production.