A driver who evacuated 40 passengers from his bus just minutes before it exploded has been praised for his actions.

Driver Stuart Jones noticed smoke and flames as he drove the double decker park and ride bus near the Postwick roundabout at about 5pm on Thursday.

Paul Bonham, commercial director for Norse, said: 'Stuart is a very experienced driver and acted very professionally by stopping in a safe place and making sure passengers left the vehicle quickly and safely. Our drivers are trained for emergencies of this sort, and this incident showed the value of that training.

'After the fire in this vehicle the engine compartments of all our other double deckers have been checked, and all have been found to be in good order.

'We apologise to the passengers on the bus for what happened, and to other road users caught up by disruption. We may never find out the precise reason for the fire, except that it was engine failure of some sort, but we do know that this vehicle had been properly maintained.'

Norwich park and ride services are provided by Norfolk County Council and Tracy Jessop, assistant director travel and transport, said she was pleased that Norse, which operates three park and ride services under contract to the County Council, had acted quickly to check all similar vehicles.

'I would also like to commend the driver, Stuart Jones, who dealt with a very difficult situation particularly well, remaining calm and taking care of his passengers. It is reassuring to all park and ride users that drivers are well trained and know exactly what to do when the unexpected happens,' she said.

Police and Highway Agency officers were at the Postwick roundabout, near the Broadland business park, following the blaze on the 605 park and ride bus just after 5pm yesterday.

Fire crews from Norwich, Sprowston and Earlham all returned to their stations at around 7.20pm,

The driver of the bus told a passerby he noticed a flame in his rear view mirror and told the passengers to get off the bus. Nobody was injured.

A council spokesman confirmed the double decker was returning to Postwick from Norwich city centre with about 40 people on board.

A statement added: 'All the passengers were safely evacuated and no injuries or ill-effects were reported by passengers or the driver. The vehicle, belonging to the Norse Group, has been burnt out and destroyed. 'Park and ride services are being maintained by diverting via the Brundall roundabout. Police are in attendance and are advising motorists to avoid the junction if at all possible.'

Witnesses said there were major traffic problems and police have deployed extra officers to help direct traffic but the incident is likely to cause delays throughout the evening.

Mel Ashford, who works at a nearby Aviva call centre, said: 'We heard a massive explosion and it sounds like something had landed on the roof.

'We rushed outside and couldn't believe the size of the fire. We saw the driver standing on the verge and he seemed to be okay.'

Witnesses reported hearing loud bangs and plumes of smoke could be seen on the city's skyline.