By David Ljunggren

OTTAWA Police in the Canadian province of Manitoba on Friday were trying to identify the 15 people killed when a truck and a bus collided in one of the country's worst recent road crashes.

Flags at the legislative building flew at half mast to mark the victims of the collision near the town of Carberry in southwestern Manitoba, 170 km (105 miles) west of Winnipeg.

The small white bus carrying 25 mostly elderly people was burnt to a charred shell. It had been heading to a casino when the accident happened.

Police said late on Thursday that they had yet to confirm any of the next of kin.

"This is something we have to make sure we get right, it has to be accurate," Royal Canadian Mounted Police Superintendent Rob Lasson told the Canadian Broadcasting Corp.

Ron Bretecher, whose parents were on the bus, told reporters that his mother had survived the crash but his father was still unaccounted for.

"(My) family's just basically waiting for word ... it's just very difficult," he said.

Lasson said police would also be looking at videos taken by passersby and talking to witnesses. Both drivers survived the crash but have yet to speak to investigators.

The bus, heading south, was crossing the Trans-Canada highway when it collided the truck that was traveling east.

Witness Nirmesh Vadera told the CBC he had been working at a cafe near the crash site when he went outside and saw a vehicle engulfed in flames.

"The fire was about 10 to 15 feet high and the smoke was almost 20, 30 feet high," Vadera said.

The crash was the worst in Canada since 16 people died in April 2018 after a truck hit a bus transporting a junior hockey team on a rural road in neighboring Saskatchewan.

(Reporting by David Ljunggren; Editing by Nick Macfie)