The bus' brakes began burning on Route 220 near Main Street in Jersey Shore Borough, Lycoming Regional police said in a release.
The bus was pulled over and passengers were evacuating when police arrived at the scene, but a passerby was injured while trying to put out the fire, according to officials.
He was treated at the scene before being taken to an area hospital, police said. He is not a student and the extent of his injuries is unclear.
The roadway was shut down while police worked the scene but has since reopened, the release concludes.
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