AN investigation has begun after fire tore through a fast food restaurant yesterday, causing damage running into tens of thousands of pounds.

Firefighters were called to McDonald's, in the Peel Retail Park, Washington, shortly after 3.30am and spent almost three hours tackling the blaze.

The restaurant had closed at about 2am and the last staff left 15 minutes later.

The alarm was raised by passers-by who saw smoke pouring from the building.

Tyne and Wear Fire and Rescue Service said yesterday that its arson investigation unit was looking into the fire, which destroyed a storage room and damaged the roof.

A spokesman for McDonald's said: "We are currently liaising with the local fire brigade to establish the cause of the fire, although at this stage it is not thought to be suspicious.

He added: "The restaurant was unoccupied at the time and, fortunately, nobody has been hurt.

"We apologise to our customers for any inconvenience caused and we will endeavour to have the restaurant open and trading as normal as soon as is safely possible."