Vandals used power tools to slice through a railway line causing chaos for freight trains in Bristol.

Saboteurs switched off power to the line, part of the Avonmouth Rail Link, before damaging the track in the early hours of Tuesday morning.

Using heavy cutting equipment, they made a series of small cuts in the rail. The weight of freight trains passing over the line then caused it to split.

Police investigating the incident, thought to have happened between 0000 GMT and 0400 GMT, say it could have caused a very serious accident.

Services disrupted

The track, at Moorehouse Lane, Hallen, has been sealed off while scenes of crime officers examine the damage.

Freight services in the area have been seriously disrupted, with trains running at 20 mph on only one of the two lines.

Detective Inspector Tony Bennett, of British Transport Police, said: "This is mindless vandalism.

"One can only assume these people were trying to derail a train, but our safety systems would not allow that to happen.

"There was no danger to people but this has caused problems for freight operators."

He appealed for anyone with information to contact the police.

"This is an isolated area, but the machinery they used must have run on petrol and noise carries so hopefully someone will have heard something and can help us," he said.

A broken rail caused a train to derail at Hatfield in Hertfordshire in October 2000, killing four people.