THIEVES risked their lives by breaking into a 6,000-volt substation to steal copper wiring worth £10,000.

The break-in, which police say was pre-planned, happened between 8pm and midnight on Sunday at the United Utilities depot in Carus Mill, Hoddlesden.

A 6,600-volt substation inside the derelict mill was switched off by the crooks before the unit was taken apart to expose the wiring.

The burglary is the latest in a string of similar offences across East Lancashire over the summer. But copycat thieves have been warned it is only a matter of time before someone is killed carrying out such a a raid.

Up to 20 houses and businesses in Johnson New Road, powered by the substation, were left without power overnight.

The utility company said the predicted loss to them was up to £20,000 for repairs and loss of income while the power was off.

Det Sgt Ian Geogarty, of Darwen CID, said a car must have been used in the getaway due to the substantial amount of goods stolen.

It is feared the wiring, which has a high re-sale value, could now be sold on the black market to workers in the building trade. He said: "These offenders knew exactly what they were doing to have successfully broken into this substation. They drilled a small hole in the brick work behind the unit and removed a low-voltage board.

"They must have been at the mill for a substantial amount of time to complete this job. We would appeal for witnesses who saw a car possibly from as early as 3pm outside the mill on Sunday.

"There is major risk of electrocution by breaking into a substation."

Last month thieves targeted an industrial unit in Widow Hill Road, Burnley, and stole £800 worth of copper.

And police are still probing the theft of £800 worth of copper from two Great Harwood factories in July and August.

Anyone with information about the latest theft should call Darwen CID on 01254 353 842.