Burning ship carrying chemicals spews toxic gas off Canada's Pacific coast

A container ship carrying mining chemicals has caught fire off Canada's Pacific coast near British Columbia posing a major environmental threat to the surrounding area.

Authorities said on Saturday that the ship had been bound for Vancouver when it caught fire.

"The ship is on fire and expelling toxic gas," the Canadian Coast Guard said in a statement on its website.

Authorities said the container ship Zim Kingston remained anchored at Constance Bank off the coast of British Columbia and an emergency zone has been established within hundreds of meters from the vessel.

It is still unclear what caused the blaze.

Local media reported that two containers loaded with chemicals weighing in total more than 52,000 kilograms were on fire.

The Canadian Coast Guard said ten containers were currently burning, adding that the fire continued to spread but the ship itself was not on fire.

The agency said it was working with its US counterpart to track 40 containers that had fallen overboard, saying they posed a significant risk to mariners.

Ten to sixteen crew members from the ship were evacuated while five others had remained behind to fight the flames.

"This is extremely concerning. The ship and containers are very close to Victoria, BC, and a big storm is forecast to hit tonight. We... are worried this may be yet another environmental disaster," said David Boudinot, president of Surfrider Foundation Canada, an environmental organization.

Eikon Refinitiv data shows the Maltese-flagged Zim Kingston is managed by Cyprus-based Danaos Shipping Co Ltd.

MG