BETHLEHEM (AP) — Police say a school bus driver suffering an apparent medical emergency crashed into a tree in Pennsylvania.

Authorities say the crash happened in Bethlehem around 3 p.m. Thursday.

At least 24 students were on the bus at the time of the crash.

The driver was hospitalized for treatment, and his or her condition has not been released. WFMZ-TV reports three students were hospitalized after one bumped their head and two others reported knee pain.

The remaining students on board were released to their parents or transferred to another bus.

The cause of the crash remains under investigation.