Almost 60 children on a school trip escaped from a double-decker bus which caught fire.
The blaze broke out at the back of the vehicle on the A1101 in Bury St Edmunds at about 10:20 BST.
A witness said he heard tyres exploding and saw diesel “spilling out” of the stricken vehicle.
Suffolk Fire Service said 58 children and 14 adults were safely taken off the coach and there were no injuries.
Firefighters said the children and teachers were given shelter nearby and a replacement bus was arranged.
Six asthmatic children were checked over by paramedics, the fire service added.
‘Diesel spilling out’
Window cleaner Sean Hale was working nearby when he saw black smoke and went to the scene at Marham Park.
“The tyres exploded in the fire and you could see all the diesel spilling out,” he added.
Suffolk Fire and Rescue Service said about 300 litres of diesel had been drained from the bus into a ditch and the Environment Agency had been informed.
Collins Coach company, which owns the bus, did not wish to comment on the incident.