(Reuters) - Four people were killed on Sunday when a bus carrying staff of the Dallas Cowboys football team collided with a van on an Arizona highway, authorities said.

Public safety officials said the four fatalities were all riding in the van. Passengers on the bus, which was transporting Cowboys staff but no players, sustained minor injuries.

Authorities were investigating the cause of the collision, which occurred on highway 93 about 30 miles north of Kingman.

No details were available about the people killed in the van.

(Reporting by Chris Michaud; Editing by Paul Tait)