A Pembroke Public Schools bus apparently caught fire with students on board while on Route 3 North, north of Exit 5 in Plymouth, State Police said. No injuries were reported.
State Police said smoke was detected on the bus, but they were unsure why, said Lieutenant Daniel G. Richard, a State Police spokesman.
A second school bus was requested to take the children to their final destinations.
State Police and the Plymouth Fire Department are currently investigating.
No further information was immediately available.