Members of the Calgary Fire Department battled a fire on a bus on a southwest street Saturday morning.

Fire crews were called to a location near the intersection of 17 Ave and 45 St SW shortly before 10:00 a.m. following reports smoke was pouring from the engine compartment of a Calgary Transit bus.

The driver and an unconfirmed number of passengers had been evacuated from the bus and Calgary Transit deployed a replacement vehicle.

Firefighters opened the door to the engine compartment and a ball of flames and dark smoke emerged. The fire was extinguished and a tow truck was dispatched to the area.

The cause of the bus fire has not been determined. No injuries have been reported.