Four people died and dozens of others were injured when the bus they were travelling on rolled over on an icy highway in the British Columbia Interior on Christmas Eve, provincial RCMP said Sunday.

The Mounties said they received multiple calls on Saturday shortly after 6 p.m. regarding the crash on the Highway 97C Okanagan Connector east of Merritt near the Loon Lake exit.

The force confirmed on Sunday afternoon that four people were found dead at the scene, but provided no details about the victims' ages or identities.

Interior Health, the regional health authority, said 52 patients were transported to four hospitals where 36 were treated for injuries that ranged from serious to minor.

It said eight people were still in hospitals in Penticton, Kelowna and Kamloops as of early Sunday morning, including two in serious condition and two with non-life-threatening injuries.

"Although the number of patients remaining in hospital is low, this is a life-altering incident for all involved, from the initial physical injuries to the emotional and spiritual impacts of an incident such as this," Interior Health said in a statement.

Mounties said the investigation into the rollover is ongoing, but said it's believed extremely icy road conditions caused the rollover.

In a statement later Sunday, police said the exact number of passengers has yet to be confirmed and officers were in the process of locating and speaking to those who were on the bus.

"Due to the exigent circumstances and injuries many were transported to local hospitals prior to police having the chance to identify them at scene," the statement said.

Police said the road conditions were described "as very poor with ice and snow on the road surface along with rain and hail falling." 

Investigators are asking anyone who witnessed the collision or who has dash-cam video of the bus before the crash to please contact their local RCMP detachment.

The bus belonged to the Alberta-based company Ebus. Director John Stepovy said the vehicle was travelling from Kelowna, B.C., to Vancouver at the time of the crash.

"First and foremost, our thoughts and prayers are with everyone that was onboard, the coach and their family and loved ones," he said.

"(We're) Certainly thankful for the first responders, RCMP, the health workers for their support and work on this and I can say that we're continuing to cooperate with the RCMP."

Ebus, a sister company of the Red Arrow bus company, offers services through the Alberta cities of Edmonton, Red Deer, Calgary and Fort McMurray, as well as from Vancouver into the interior of British Columbia.

Interior Health implemented a Code Orange response— signalling a disaster or mass-casualty event — in the hours following the crash. Additional critical care staff in areas including emergency departments, medical imaging and surgery were brought in.

DriveBC, the communications arm of the B.C. Ministry of Transportation, said the stretch of road was cleared and reopened shortly before 8:30 a.m. local time Sunday.

The ministry released a traffic advisory after the highway reopened warning of poor driving conditions on highways in the southern Interior due to snow and freezing rain.

The ministry urged drivers to avoid non-essential travel, use caution and be prepared for highway closures on short notice if they must be out on the roads.

B.C. Premier David Eby, Public Safety Minister Mike Farnworth, Health Minister Adrian Dix and Minister of Transportation Rob Fleming released a joint statement Saturday evening expressing their shock and sadness over the crash.

"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,” the statement read.

This report by The Canadian Press was first published Dec. 25, 2022.