Four people are believed to have been killed when a US air force (USAF) helicopter crashed, police have said.

The aircraft came down in Cley-next-the-Sea in north Norfolk, on the east coast of England. Emergency services are at the scene with a 1,200ft (400m) area cordoned off.

The helicopter is an HH-60G Pave Hawk, based at RAF Lakenheath in Suffolk, a spokesman for the USAF confirmed.

Superintendent Roger Wiltshire said the crash took place on land.