A school bus collided head-on with a tree-trimming truck early Tuesday, injuring 18 people, most of them students who were taken to area hospitals.

The extent of the students' injuries and their ages were not immediately known.

The crash was so severe that the bus driver, William K. Hall, had to be cut out of the bus, the Logan County Sheriff's Department said. His injuries were not considered life-threatening, said Rodney Smith, a spokesman for Williamson Appalachian Regional Health Care Hospital, just across the state line in Kentucky.

The students and the truck's driver were taken to other hospitals, where their conditions were not immediately known.

The bus was taking 15 students to the Mingo County Career and Technical Center in Delbarton when it was collided with the truck about 8 a.m. on state Route 65 in Lenore, officials said.