SP S M H Mirza said a big police contingent, led by Additional SP Tarun Halder, later brought the situation under control.
Altogether 25 persons were arrested from the area in connection with the arson and violence, Mirza said.
The mob was protesting the death of a local youth Pappu Pal who was knocked down by a sand-laden truck.
Sub-Inspector of Khandagosh police station Mohammed Jalal, who had initially gone to the area, has not been given any duty and sent to the police lines pending further inquiry, the SP said.
The fire of the police jeep was put off by a fire tender which rushed to the spot under police escort.
