POLICE have said it was only luck that prevented a catastrophic accident after a train hit a wooden sleeper that had been deliberately placed on tracks by vandals.

The driver of the train, a rush-hour Newcastle to Middlesbrough Northern Rail service, was forced to make an emergency stop, but could not prevent a collision.

However, the passengers onboard escaped unhurt following the incident, at Blackhall Viaduct, Peterlee, County Durham.

British Transport Police have only just released details of the accident, which happened at 5.10pm last Friday, and have issued an appeal for witnesses.

They said the driver of the train got out of his cab to check the area and discovered a fence and stones had also been placed on the tracks.

Police officers who were called to the scene searched the area, but found no trace of any suspects.

A member of the public had earlier reported youths messing about on the railway line.

The railway sleeper, which is thought to have shattered, caused only minimal damage to the train.

PC Graeme Cooper, of British Transport Police, said: "It is vital that we find those involved in this incident in order to point out the possible catastrophic consequences of their actions.

"Luckily, the sleeper caused minimal damage to the train, although the situation could have been a whole lot worse.

"I would urge anyone who was in or around that area at approximately 5pm to contact us if they saw the anything suspicious, or have any information that may help us with our inquiries."

PC Cooper said the train had been travelling at 60mph before the driver applied the brakes.

He said: "He managed to lose enough speed not to cause a derailment.The obstruction could easily have thrown the train off course."

The weight of the sleeper was such that several people would have probably been needed to lift it, he added.

The North-East traditionally has the worst record of any region in the country when it comes to problems with rail vandalism and trespassing on tracks.

Two years ago, The Northern Echo teamed up with Network Rail to support its No Messin' campaign, highlighting the dangers of such behaviour and promoting the opportunities for safe play for youngsters.

Anyone with information about the Peterlee vandalism is asked to call freephone 0800- 405040 quoting incident number 438 8/6/2007. All calls will be dealt with in strict confidence.