The bus, belonging to a travel company, was completely gutted. Volvo Buses, the manufacturer firm, said it was an isolated instance and it was waiting for further details to emerge.
The incident occurred sometime after 7.30 am near Chiragpally, said circle inspector S Lakshminarayan of Zaheerabad police station.
The Mumbai-Hyderabad bus was carrying 45 passengers besides the driver and the cleaner (assistant).
"The driver noticed flames on rear-engine side, so he stopped the bus and immediately alerted the passengers who got down with the luggage. The fire spread inside and it got completely burnt," he said, adding,"No one was injured."
As many as 45 passengers had died after a Volvo bus belonging to another private company caught fire in Mahabubnagar district of Telangana on October 30, 2013.