A tractor and a truck collided in?Gansu Province Wednesday afternoon, leaving five dead and four others injured, local authorities told Xinhua.

The heavy-duty tractor and the truck collided at 1:15 p.m. on the highway in the city of Wuwei, leaving five people dead and four slightly injured, said an official with the municipal administration of work safety.

The nine dead or injured people had been in the truck, the official said.

The injured have been hospitalized, and an investigation into the cause of the accident is underway.