The Japan Times - Police positioned to clear key border bridge of protesters in Canada: AFP journalist

"We urge all demonstrators to act lawfully & peacefully," police in Windsor, Ontario tweeted in announcing the deployment.

The normally busy Ambassador Bridge links Windsor to the US city of Detroit, Michigan.

Dozens of police officers and vehicles had arrived on the scene by 8:00 am (13H00 GMT) and begun taking positions near the approximately 50 protesters whose big trucks, vans and pick-ups have blocked the major trade link for six days.

On Friday, the Supreme Court of Ontario province ordered the demonstrators to end their blockade.

With the protests increasingly impacting the US auto industry, US President Joe Biden's administration has implored the government of Prime Minister Justin Trudeau to end the blockage.

But those occupying the Ambassador Bridge seemed largely unmoved.

The protest has affected automakers on both sides of the border, prompting Toyota to pause some production in Canada and Ford Motor Company to fly parts in, the Windsor Star newspaper reported.

The industry, one of the most important in Ontario, was already facing serious challenges from Covid-19, supply-chain disruption and bad weather.

Ontario premier Doug Ford has warned protesters that they could face fines of up to Can$100,000 ($78,500), up to a year in prison and revocation of their driver's licenses if they continue blocking traffic.

Protests began about two weeks ago when truckers drove into capital city Ottawa to demand an end to a vaccination requirement affecting truckers crossing the international border.

But the movement has spread to several other cities and border crossings, and copycat protests have now sprung up in other countries such as France and New Zealand.

The Canadian protesters -- mostly insisting they want to protect their freedoms, but some displaying swastikas or Confederate flags -- are now demanding an end to all vaccine mandates, whether imposed by the federal or the provincial governments.

S.Yamamoto--JT