Co-op staff at Didcot returned from the Bank Holiday to find the rear of the supermarket in Market Place splattered with yoghurt, eggs and other foodstuffs.

Assistant manager John Hayter said he and colleagues spent more than two hours cleaning up the mess, which included rubbish from a large covered skip which was strewn over the rear unloading bay of the supermarket and neighbouring shops.

"It was a dreadful mess," said Mr Hayter, who blamed youngsters congregating around shops in the Market Place during the day and evenings.

"They are mostly in the ten to 14 years age bracket," he said. "They are swearing and abusive to customers outside the supermarket. If we call police, the kids seem to think everyone is powerless to deal with them."

Mr Hayter said staff had become acutely aware of the problem during the Easter holidays, although it was also happening during term time.

Mr Hayter and other shopkeepers said the problem coincided with a rise in shoplifting by youngsters stealing goods including toasters and other electrical goods.

Insp Ian Beckett of Didcot Police said patrols would be stepped up.