PARTS of Darlington had to be sealed off yesterday after a small explosion in the town centre.

It is believed water got into a high-voltage power cable, causing smoke and flames to shoot from a street sign.

Homes and businesses were without electricity for 45 minutes as a result of the incident. Last night, electricity supplier NEDL said it was investigating the cause of the power cut.

Darlington's main post office, in Crown Street, was also affected and had to close for a time.

Witnesses reported seeing a jet of flame up to 10ft high shooting from the top of the street sign at about 11.30am. Shortly afterwards, police and fire crews were at the scene, outside mobile phone store Phones4U.

Watch manager Andy Bruce said: "The plastic cap blew off the sign and there were flames which shot 10ft in the air.

"There's been no smell of gas, so we don't think it's a gas leak.

Police and fire crews sealed off the town centre around Priestgate and in the public performance space in front of the Joseph Pease statue.

A spokeswoman for NEDL said: "At 11.28am we were notified that 528 customers in the Darlington area were without power.

"We had phone calls from customers in the Cornmill, Hundens Lane, Prebends Row and Priestgate area.

"Engineers found that there had been an underground fault.

"We restored all the supply that was interrupted by 12.14pm.

"We apologise to all those who were affected."

A spokeswoman for Darlington Borough Council said: "We have been advised by electric company staff on site that this incident appears to have been caused by water which had got into a high voltage power cable underground, possibly as a result of the bad weather recently.

"It was not in any way as a result of work being done today in Tubwell Row.