Three valuable paintings by LS Lowry showing his trademark industrial scenes of north west England have been stolen from a gallery that has been open for just one week.

Thieves forced their way into the Clark Art Gallery, in Hale, by using a drain cover to smash a front window and stole a total of 15 pictures from the wall, before driving away in a dark-coloured vehicle.

The Old Trafford born artist’s famous Industrial Scene, Industrial Scene With Figures and Two Women And Children, along with two paintings by Helen Bradley and one by Sir Terry Frost, were among those stolen with an estimated total value of £300,000.

Lowry, who died in 1976, was famous for his pictures of working class life in Lancashire and Cumbria. The "matchstick men and matchstick cats and dogs" in many of his drawings and paintings were immortalised in a 1970s hit by Brian and Michael.

Bill Clark, the gallery owner, who is offering a £25,000 reward for information leading to the return of the paintings and the conviction of the thieves, said: "It is devastating to have this happen after one week’s trading.

"The thieves have targeted paintings and drawings by LS Lowry, Helen Bradley and Sir Terry Frost. I can’t understand how they are going to sell them on as they are all very well-known works."

The three men are described as aged between 18 and 23, 5ft 9in to 6ft, and of athletic build. They were wearing dark-coloured clothes and face coverings.

Detective Constable Neil Rothwell, from Trafford CID, said: "I would appeal to anyone with any further information about this incident, or who may have been offered the paintings, to contact CID at Stretford on 0161 856 7672 or Crimestoppers anonymously on 0800 555 111."