A £5,000 reward is being offered to help catch crooks who have stolen goods worth £500,000 in shop raids across the North-East.

Seven Woolworths stores in an area from Bishop Auckland, County Durham, to Blyth, Northumberland, have been targeted by the gang.

The thieves are targeting expensive entertainment products such as DVDs, computer games, mobile phones, videos and CDs.

A spokeswoman for the store chain said: "We have offered a £5,000 reward to help police, both the Northumbria and Durham forces, for information which leads to an arrest."

The latest raid happened overnight on Saturday at the firm's store in Newgate Street, Bishop Auckland.

A Durham force spokesman said: "More than £30,000 worth of goods were stolen, including mobile phones, PlayStations, DVDs and phone cards.

"The thieves used the same method of operation as they have in other raids."

Police believe the thieves are professional - possibly stealing to order - and know how the stores' alarm systems work.

In some cases they have broken in through the roofs and smashed walls and doors to get to the goods.

The Durham force spokesman added: "Some stores in the Northumbria Police area have been broken into two or three times.

"We are liaising with Woolworths and Northumbria Police over the burglaries, and we need to speak to anyone who has been offered this sort of property for sale.

"We also need any information about the men responsible and where they may be based."

The Woolworths spokeswoman said: "To combat the burglaries we are upgrading alarms systems and reinforcing other points of entry."

Other stores targeted are at Wallsend and North Shields, North Tyneside; Gosforth, near Newcastle; and Consett and Spennymoor, County Durham. There has also been a raid at a branch in Carlisle, Cumbria.

Anyone with information is asked to call police on 0191-386 4929 (Durham) or (01661) 872555 (Northumbria), or to call Crimestoppers anonymously on (0800) 555111