Six people have been injured in a crash on the Trans-Canada Highway just east of Moose Jaw.

Police said it happened on the bridge crossing the Moose Jaw River on Highway 1 at about 5:30 p.m. CST.  

An SUV pulling a camper trailer flipped on its side on the highway, blocking the eastbound lane.

A witness told the CBC News a semi had clipped the side of the SUV, causing the crash. At least seven police cars were observed at the scene.

Police are looking for a semi tractor with blue lettering on the cab, pulling a white trailer. Officers said the vehicle was involved in the crash, and it was last seen travelling eastbound.  

The six people injured are being treated at the Moose Jaw hospital.

Police advised motorists to take a lengthy detour north towards Chamberlain, Sask. on Highway 2, before heading south to Regina on Highway 11.