The incident occurred in the bus running on route number A-288 of Magathane depot.
At 6pm, when the bus reached near Alika Nagar junction in Kandivali, the driver observed a spark in the bus battery.
“He immediately stopped the bus and evacuated the passengers,” an official said.
Meanwhile, he doused the fire with the help of the fire extinguisher kept inside the bus.
“There is no injury to anyone, including driver, conductor and passengers,” the official said, adding, “We have reported the incident to the private contractor who is running the bus service on wet lease for BEST. He has been directed to conduct technical inspection in all buses being operated by him in western suburbs.”