The operator of a bus that caught fire outside Minchinhampton has reassured parents it is investigating how it happened.

"We have already begun an investigation into the cause of the fire and determined to ensure that such an event does not recur," said Rob Arkell of Cotswold Green Ltd in a statement to the SNJ.

His company runs the 128 bus from Cirencester to Nailsworth that was carrying some students from Deer Park when its engine caught fire yesterday afternoon.

Year 11s at the back of the bus first noticed smoke through the rear window.

"I thought the boys were joking - and then I saw the smoke coming through the seats," said Ellie Sanders, a Year 11 at Deer Park who lives in Avening

"It absolutely stank, really chemically.

"We all started shouting to the bus driver 'Your bus is on fire and you need to stop!' as it started to fill with smoke."

All of the passengers and the driver were able to evacuate the vehicle safely before a fire crew extinguished the blaze.

Mr Arkell continued: "We are very grateful for the unbelievably quick response from the fire service, the calmness of our bus driver in such challenging circumstances and we are also grateful to our passengers for evacuating the vehicle in such an efficient manner.

"We are also thankful to the members of the public who stopped to assist."

Some parents of the students on board have taken to the company's Facebook to voice concerns.

"This incident could have been much worse - I am thankful everyone is safe but lessons need to be learned," posted Ellie's mum Amanda.

"If this was a train or plane there would be questions asked - this is a public service and answerable to us, the public, their customers."