In the United States, at least nine people, mostly high school students, have died in a collision between a trailer and a tour bus.

Most of the victims were college hopefuls on a campus tour in Sacramento in northern California.

Pictures from the scene showed the bus reduced to a burned-out chassis resting sideways across the highway.

More than 30 others were hurt as the driver of a FedEx truck lost control and crossed a junction on Interstate 5, hit a car and then smashed head-on into the tour bus.

No one in the car was killed, although the driver was sent to hospital with unspecified injuries.