MERRITT, B.C. -- The British Columbia government plans to audit a bus company involved in a serious weekend collision in the province's Central Interior that sent more than three dozen people to hospitals across the region.

The province's Ministry of Transportation and Infrastructure said in an emailed statement that its investigation of Universal Coach Lines will include a review of the company's drivers.

"An audit is standard for operators involved in this type of incident," read the ministry statement.

Police say that shortly before 10 a.m. on Saturday a tour bus rammed into a car and a tow truck parked on the shoulder of the Coquihalla Highway, about 40 kilometres south of Merritt, B.C.

The collision left 38 people injured, including two who were airlifted to hospital in serious condition.

RCMP Cpl. Chris Newel said charges are expected but that it could be weeks before any are laid while an investigation continues into the cause of the crash.

"There are still lots of questions to be answered," said Newel on Sunday.

Universal Coach Lines is based out of Richmond, B.C., and operates a fleet of 80 vehicles throughout B.C., Alberta and Washington state, according to the province's Transportation Ministry.

An initial review of the company's safety record indicated there had been "no major incidents or concerns in recent years," said the ministry's statement.

The ministry added that commercial-vehicle safety officers would work with the RCMP in the coming days to investigate the crash, which would include a "more fulsome review" of the company's safety record.

By Sunday morning nearly all of the 25 people taken to hospitals in Merritt, Kamloops and Kelowna had been released, said Darshan Lindsay, a spokeswoman for the Interior Health Authority.

"We have two patients remaining in hospital in Kamloops and Kelowna," said Lindsay. "The remainder were discharged throughout the day and into the evening and night yesterday."

The other 13 people injured in the crash were taken to hospital in Hope, B.C., though the Fraser Health Authority was unable to say how many remain in care.

An employee at Mario's Towing confirmed the crash involved a truck belonging to the Kelowna-based towing company. Universal Coach Lines declined comment.

Newel said the car's driver was parked on the side of the Coquihalla and had called for a tow truck after hitting a deer. The truck driver was outside talking to the occupants of the car when the bus struck, he said.

Newel said the RCMP received reports that the tour guide was ejected from the bus and ended up in a creek below the highway.

The guide and tow truck operator suffered serious injuries but are expected to recover, while the car's driver and passenger were also injured, he said.