The return of winter weather caused a number of vehicle crashes Wednesday morning.

"Currently, road conditions remain very poor around the province. Ice-covered highways and reduced visibility are dangerous for motorists. The RCMP have responded to multiple collisions throughout the morning and continue to ask motorists to use extreme caution while travelling," said the RCMP in a statement.

A transport truck jackknifed on Highway 1, east of Highway 5. According to RCMP, there were no serious injuries reported. 

A transport truck also jackknifed in Headingley and was hit by another truck. Details are scarce, but RCMP say there were no serious injuries.

According to police, one person was taken to hospital after a school bus rollover on Highway 75 South. More than 10 other adults were treated on scene. There were no children on board.

"If you can avoid travel, please do. If you must be out on the roadway, slow down. Posted speed limits are for ideal conditions," said RCMP. "Be aware of areas that tend to be more treacherous, such as bridges, overpasses and open areas with no wind block. Increase the distance between your vehicle and others around you. Increase your braking distance, as the space you need on an icy road is double the stopping distance needed on a dry one."

At about 7:45 a.m, a woman and two children were extricated from a vehicle in a water-filled ditch on McPhillips St. near the Perimeter Highway. RCMP said there were no injuries.

Between 6 a.m. and 11:15 a.m. Wednesday, RCMP responded to 21 crashes around the province.

People can get details on highway conditions by calling 511, online at www.mb511.ca or by following the Twitter account at www.twitter.com/MBGovRoads.

MPI expects to open about 600 claims on Wednesday.

Spokesperson Brian Smiley said, following a bad winter storm, that number usually spikes to 1,000.

Still, he advised motorists to drive to the conditions.

"You've got slush out there. It's going to freeze. You've had some falling snow, so it's a real challenging driving day,” said Smiley.

- with a report from Ben Miljure