A minibus on the Howrah-Harinavi route caught fire near pillar No. 17 of the Howrah bridge around 5.20pm, police said.
The driver spotted thick fumes coming out of the engine and asked passengers to get off the bus. The bus was headed for Harinavi, South 24-Parganas, when the fire broke out.A police team reached the spot and helped in fighting the fire. But by then the entire bus was on fire.
Two fire engines brought the fire under control in 20 minutes, the police said. No one was injured. The police had to divert city-bound traffic till the bus was towed away. Forensic experts will inspect the vehicle on Friday.