A double decker bus full of school children has caught fire at the M25 Maple Cross junction.
Police and firefighters were called to the junction 17 entry slip road anticlockwise at about 10.30am following reports a coach was on fire.
Around 40 children had to be evacuated from the bus while fire crews dealt with the blaze, which started at the vehicle’s brakes.
Police closed the sliproad and escorted the children to safety. It is understood none of the children sustained injuries.
Andrew Dawson, spokesman for Hertfordshire County Council, said: "There was a coach that had its brakes overheating.
"We requested police assistance for the 40 school children who were on the coach and needed to be gotten to a place of safety.
"We sent three crews, one from Rickmansworth, one from Watford and one from Garston stations.
"One hose reel was used to deal with the fire."
Hertfordshire Constabulary spokeswoman Sarah Spence said a second bus was en route to the children at 11am.
She said: "We were called at 10.35 this morning by the fire service to the M25.
"It was given as a coach fire near junction 17 entry slip road to the motorway.
"The fire service asked us to close the slip road so the children could be moved to safety.
"A second bus was en route just before 11 o clock to collect the children. The vehicle on fire was described as a double decker bus."
The blaze was extinguished at 10.54am and has now been recorded as an "accidental fire".