Twenty-five passengers, including the driver of a private air-conditioned bus, escaped unhurt after the vehicle caught fire early on Friday on Hyderabad-Mumbai highway in RC Puram here. Police said that at around 6 a.m., when the bus was in TSRTC bus depot in the area, the driver noticed smoke coming out of the bonnet and alerted all passengers, who immediately evacuated the bus before it was reduced to ashes. The bus belonging to Orange Travels was proceeding from Mumbai to Hyderabad. Officials suspect that electric short circuit could be one of the causes for the fire. However, the exact reason is yet to be ascertained. “Soon, a fire tender was rushed to the spot to douse the flames,” RC Puram police of Cyberabad said.