The protest blocking freight traffic from Detroit into Ontario is starting to hit crucial supply chains, as Ford Motor Co. was forced to idle a Canadian engine factory and operate an assembly plant at reduced capacity.

Ford’s engine plant in Windsor, Ontario, is shut down and the schedule cut back at a factory in the Toronto suburbs that makes the Edge model, spokesperson Said Deep said Wednesday in an email. The automaker is continuing to ship engine inventory to U.S. plants, he added.

The blockade of the Ambassador Bridge between Detroit and Windsor by protesters angry over COVID-19 restrictions is in its third day, with no end in sight. Windsor officials said Wednesday they prefer a negotiated settlement over using force to tow away the vehicles that have clogged the city’s streets and prevented trucks from crossing the border.