The Ohio Highway Patrol says a tractor-trailer jackknifed, swerved into oncoming highway traffic and collided with a small bus transporting disabled passengers, killing four people in the bus.

The accident occurred Thursday afternoon on Interstate 70 near Springfield in southwest Ohio. There was snow on the roads and it has been snowing steadily throughout the region for hours.

Clark County coroner's investigator Michael Haytas says the four dead are adults and their identities have not been confirmed.

Patrol Sgt. Raymond Durant says the tractor-trailer was heading west when it crossed the highway median and clipped another vehicle and struck the 17-passenger bus.

Durant says among the dead is the bus driver. He says six others were injured, including the driver of the truck.