Four people were killed and dozens injured after a passenger bus overturned west of Canada, where it was suspected that ice accumulation on the roads was the cause of the accident.

The accident occurred on a highway east of Vancouver in British Columbia, which has been experiencing stormy weather for days.

The Canadian police said on Sunday afternoon that they suspect that the "severely icy road conditions" caused the bus to overturn, but the investigation is ongoing.

They added, "Four people have been confirmed dead and many passengers injured."

The regional health authority reported that 53 injured received treatment in hospitals, including 36 with injuries ranging from "serious to minor."

Eight people remained in the hospital, two of them in critical condition.

British Columbia Premier David Eby expressed his "shock and sadness."

The accident occurred at a time when bad weather dominates vast areas of North America, causing transportation disruptions and many fatal accidents during the holiday season, which sees heavy traffic.

On the other side of Canada, train traffic between Ottawa and Toronto was disrupted over the weekend due to fallen trees and power outages caused by the storms.

Canadian Prime Minister Justin Trudeau wrote on Twitter, "To Canadians affected by winter weather across the country... please stay safe."