UP to 100,000 homes and businesses across the region were left without power due to a fault on the National Grid.

In North Yorkshire, the police headquarters was evacuated and eight people had to be rescued from a lift in Middlesbrough when two power stations went off the National Grid at about 11.30am yesterday.

An automatic response meant that parts of the region were disconnected from their supply until the problem was fixed.

The cuts caused disruption as firefighters were called out to attend automatic fire alarms.

In Durham, the fire brigade was called to two incidents of automatic fire alarms, and firefighters in Cleveland attended seven which were triggered by the power cut.

The Cleveland fire brigade also had to attend two lift rescues, as they stopped in mid-action.

In one, there was no one inside, but eight people were rescued from a lift at Whinney Banks Library, in Middlesbrough.

Up to 500 police officers and staff were evacuated when the power cut triggered a fire alarm system at North Yorkshire Police's base, at Newby Wiske Hall, near Northallerton.

A police spokesman said: "The power outage triggered the fire alarm, which led to the building being evacuated while the power cut was investigated.

"The cause of the problem was a computer server in the information services department.

"Although the press office telephone was not able to be answered, calls to the force control room, which deals with calls to the 999 emergency and 0845 numbers, were not affected."

Newby Wiske is not an operational police station, so there was no issue with prisoners either being evacuated or left unsupervised, said the spokesman.

North Yorkshire County Council's headquarters, at County Hall, in Northallerton, was also affected by the power cut.

A meeting of the authority's executive was briefly interrupted when the lights went out. In the town's high street, staff at Barclays bank were left to process many transactions by hand, after the blackout put the branch's computer system out of action.

Newcastle International Airport suffered a 40-minute power cut from about 11.40am. An airport spokeswoman said a back-up system of emergency generators for the terminal building immediately kicked in. The main system was brought back online at about 12.20pm.

Electricity distribution company NEDL said about 100,000 customers were affected by the power cut, with the majority on Teesside and Tyneside.

Most were reconnected with their power within a few hours.

A spokesman for the National Grid said the two power stations, which they are unable to name for commercial reasons, went off line within a few minutes of each other.

The result was a drop in the frequency of the National Grid.

A spokeswoman said: "Our system operates so that it automatically starts disconnecting some areas of demand to bring the frequency back to a safe level.

"The way it works is so it is not one area as a whole which is affected. There were other areas affected including London and the North-West."

A spokesman for the North-East Chamber of Commerce said: "A loss of power can be very disruptive to businesses.

"Large companies might have a backup generator, but for smaller companies that don't have that facility it can grind their businesses to a halt.

"A lot of large businesses like to have a disaster plan in place, but for something like this smaller businesses can suffer.

"It depends on how much you depend on power. But for most businesses that are run by computer, you need a power supply.