The incident happened around 11 p.m. Friday near 2nd and Monroe streets.
Police say the speeding car rammed into the back of the bus.
The suspects then got out of the car and made a run for it, police say.
Police quickly caught them.
The driver of the bus was just returning to the bus garage when the incident occurred.
He was taken to Christiana Hospital for treatment, and is expected to be OK.
Investigators have not said why police were pursuing the car.