A Ford Galaxy people carrier, believed to be carrying six passengers including at least one in a wheelchair, caught fire while travelling on the A47 towards Wansford from Peterborough at about 2pm on Saturday.

Gary Jelly, 39, spotted the flames as he was travelling in the opposite direction on the dual carriageway.

Mr Jelly, from Leicester, pulled over, jumped out of his car and sprinted across four lanes of traffic on the busy road.

He said: "I was first on the scene and when I got there I could see a few small flames coming from the bonnet.

"There were five or six people in the car, one of whom was in a wheelchair, and I made sure they all moved away from the scene, as I could see that the fire was starting to spread."

Shortly afterwards, an ambulance arrived and Mr Jelly said he started to stop traffic from driving past. He said: "One driver wanted to go past, but I stopped him, because if there was an explosion as someone was passing, they could have been hit by flying debris.

"Shortly after that there was the first explosion, which I think was the tyres. There was a loud bang, and flames started shooting up. They were 15ft high at one point."

Then, minutes later, said Mr Jelly there was a bigger explosion, coming from the engine.

He said: "There was a much louder bang and more flames. After that the car was completely engulfed.

"I spoke to the driver and she said something went under the car a few minutes before, and then she heard a bang, so she pulled over. It is lucky she did."

Traffic queued back for more than two miles while firefighters tackled the blaze, causing major disruption throughout the afternoon. It is not the first time Mr Jelly has rushed to help drivers in trouble.

He said: "In the past I have helped a woman who had tipped her car, and a lad who rolled over.

"On Saturday I was with my wife, Tracy, and she was panicking because she knew I was going to go and help, and was worried I was going to get hurt. But she was proud of me once we got home."

Nobody was hurt in the incident.