Twenty-one elementary students and a bus driver were injured after one school bus rear-ended another in Washington state.

Renton School District spokesman Randy Matheson says the buses were picking up students from local apartment complexes at about 9:30 a.m. Friday when one bus ran into the other.

The collision happened at a pick-up point at one of the apartments as the buses were heading to Lakeridge Elementary School. Renton police and fire units responded and checked out the children at the scene.

Matheson says 11 students were taken to a local hospital with minor to moderate injuries. Ten other students were taken by their parents to local clinics or private doctors.

He says one of the bus drivers also went to the hospital with a minor to moderate injury. The other driver was OK.