The screen was taken while paramedics were treating a man with a suspected broken leg at Horsford near Norwich.

The attack came just 48 hours after another screen was ripped from an ambulance car in Thetford, Norfolk.

Rob Lawrence, director of East Anglian Ambulance NHS Trust, said the screens cost £260 to replace and mean the vehicles are off the road for repairs.

"The price of replacement is nothing compared to the potential cost of human life should an ambulance be out of action.

Beggars belief

"These screens are not portable and they are not transferable. They are screwed into the ambulance cab and attached to an integral system within the vehicle's bodywork," he said.

"It really beggars belief that anyone would steal something from an ambulance - especially while the crew is away trying to help a patient in quite serious pain."

The second theft happened at about 2300 BST after the vehicle arrived at the pub in Horsford and before it left for the Norfolk and Norwich University Hospital.