LONDON (AP) _ A bus overturned and crashed in western England Tuesday afternoon, killing at least 10 people, police said.

Another 20 people were injured in the crash, one critically.

``It was sheer carnage,'' said John Dando, a fire official in Avon. ``The roof had partly collapsed on to the body of the coach, and most of the windows were broken. With so much twisted metal and broken glass there were many laceration injuries.''

The bus, carrying at least 29 passengers and the driver, overturned into an embankment as it approached an interchange on the M4 Highway about 120 miles west of London.

Press Association, the British news agency, said the bus was carrying a Royal British Legion group from Christchurch in southern England. The pensioners had been on a day trip to Cardiff, Wales.

The cause of the crash was not immediately known.