Bus bursts into flames on Sydney motorway

Eleven people have escaped uninjured after a charter bus burst into flames on Sydney's M4 motorway.

Firefighters were called to an off-ramp near Homebush Bay Drive after 7am on Wednesday to find the back of the bus well alight.

The driver and 10 passengers escaped, but the incident caused traffic delays as a plume of black smoke billowed from the back of the vehicle.

The blaze has been put out but the off-ramp remains closed.