“Extremely icy road conditions” are believed to have caused the vehicle to roll over near the town of Merritt on Saturday, police say.

Temperatures had dropped to -3.9C in the area, about 220 miles (360km) from the provincial capital, Victoria.

Provincial premier David Eby expressed shock and sadness at the news.

“Our thoughts are with those impacted by the crash, their loved ones, and the first responders and health-care workers giving their all to treat people and keep them safe,” he said.

The westbound coach had been travelling from Kelowna to Vancouver when it crashed on the Okanagan Connector, part of Highway 97, shortly after 18:00 (02:00 GMT Sunday), Global News reports.

A total of 52 people were sent to hospital as a result and 36 required treatment, health officials say. As of Sunday afternoon local time, eight people were still in hospital, two in serious condition.

Police said their investigation into the crash, which involved no other vehicle, was continuing.

All railway services between Canada’s two biggest cities, Toronto and Montreal, were cancelled for Christmas Day after a train derailed in poor weather conditions.