The crash occurred at about 6 p.m. local time near Salthouse on the Norfolk coast, a statement from the U.S. Air Force said. The aircraft was based at the nearby Royal Air Force station in Lakenheath, Suffolk County, which hosts USAF units and personnel.
The helicopter, assigned to the 48th Fighter Wing, was flying low at the time of the crash, the statement added.
In Washington, a U.S. defense official said the accident killed the four U.S. Air Force crew members aboard. The official spoke on condition of anonymity because he was not authorized to discuss the crash publicly.
Emergency workers from the fire brigade, coast guard and police are at the scene. Police in Norfolk County said they believe there is ammunition onboard the helicopter, and the scene was cordoned off so that experts could ensure the area is safe. Apart from the crew, nobody was put in any danger, police said.
It added that family members will be notified before details on the victims can be released.
Painful for the families of the dead.