Almost 40,000 homes and businesses in Bradford were left without power yesterday after a suspected vandal attack on an electricity pylon.

Customers in the south-western area of the city were plunged into chaos when supplies went off shortly before 8.30am.

More than 38,500 premises were hit in the Dudley Hill, Wibsey, Odsal, Low Moor, Tong Street and Spring Mill Street areas and 20 sets of traffic lights between St Stephen's Road at West Bowling and the Mayo Avenue roundabout at Odsal went out, causing gridlock on Manchester Road for more than three hours.

Electricity engineers restored supplies to nearly half of its customers within minutes of the power cut but it was mid-afternoon before all the power was back on.

A spokesman for CE Electric UK, distributors for the Yorkshire region, said the interruption had been caused by a wire coming down on an overhead pylon carrying 132,000 volts in a field next to the Yorkshire Martyrs Collegiate College playing fields off Westgate Hill Street.

She said there had been a higher than normal number of incidents of vandalism during the summer and there was evidence of metalwork on the ground under the damaged pylon.

She said: "An investigation is under way and we don't know what has caused it yet. But we wont be ruling anything out until the investigation has been completed and vandalism is an option which is being looked into."

The spokesman warned that vandalism was not only an inconvenience to customers but was dangerous to those who carried it out.

"All our pylons and electricity sub stations have danger of death' signs on them and they mean what they say. You put your lives at risk if you mess about with electricity equipment."

She said staff had responded "brilliantly" to the power cut and had restored supplies very quickly.

"We want to apologise to all our customers who were affected and assure them we have done everything in our power to get them back on as quickly as possible," she said.

A spokesman for Bradford South Police said the loss of the traffic lights had caused delays for more than three hours and officers had had to direct traffic, but no accidents had been reported.

e-mail: steve.wright@bradford.newsquest.co.uk