FOUR teenagers are lucky to be alive after the car they were in crashed and burst into flames, police say.

The accident, near Cwmbran last night, left one young man in hospital and three other people in their late teens suffering minor injuries.

Two young women - one from Newport and the other Cwmbran - and two men from Pontypool, were in the 3-series BMW when it crashed on Greenforge Way, between Springvale and the Greenmeadow community farm roundabouts.

Sergeant Andrew Lloyd, of Cwmbran police, said the BMW crossed the three lanes of road, collided with a lamppost and then a tree before bursting into flames at 11.30pm.

The road was closed until 2am while a fire crew from Cwmbran put out the fire and police accident investigators looked for clues as to how the accident happened.

One of the male passengers suffered a badly broken leg in the accident.

The other three passengers received minor injuries. All three were taken to the Royal Gwent Hospital, Newport, by ambulance for treatment.

Sergeant Lloyd said: "They were lucky to get out. The impact was on both sides. They hit the lamppost first, which spun the car, which led to the car hitting the tree. The impact was on the door locks of the car. The doors were jammed shut."

He added the occupants had managed to get out of the car before police arrived.

"They got out through the windows," he said. "All are lucky to be alive."

Sergeant Lloyd said the cause of the accident is unknown.

He added there was no suggestion the car was being driven at excess speed and drink driving has also been ruled out.

The BMW - which was very badly damaged in the accident - was being followed by another vehicle carrying the four teenagers' friends.

The second car was not involved in the accident.