The BBC's Penny Roberts: Offenders face life sentences

The train ploughed into the car on Monday night, setting the train on fire, but leaving passengers unharmed.

The crash site at Cwmbach, near Aberdare in south Wales, is only yards from a petrol station.

Superintendent Tony Thompson, of British Transport Police, said: "It was stupidity beyond belief - and really a miracle that no one was hurt."

The train was set on fire

The vandals had dumped the car on the track in darkness.

But the driver spotted it and braked to 30mph before the collision as Cardiff Railway's 1645 service from Barry Island to Aberdare, south Wales, approached Cwmbach.

Railtrack praised the shocked driver and conductor for swiftly evacuating passengers to safety.

Spokesman Eryl Jones said: "The consequences could have been extremely dire.

"Whoever deliberately put the burning car on the line was obviously intent on causing chaos and a very serious incident."

Transport police said the culprits face charges of endangering passengers' lives - a crime which can carry a life sentence.

The car, a Ford Sierra, was stolen from the Aberdare area just 15 minutes before the crash.

Officers appealed to anyone with information to phone 0800 281175.