The bus of a private engineering institute was coming to Berhampur from Lathi on the outskirt of the town when the mishap took place yesterday, they said.
At the time of the mishap, only three students were in the vehicle and all of them as also the driver and helper got down as soon as it caught the fire, said officer in charge, Goshaninuagon police station R K Murmu.
The electric supply was disrupted in the area for several hours, sources said.