Britain's defense ministry says a Royal Air Force training helicopter made an emergency landing on a mountain peak in Wales and then burst into flames.

The Ministry of Defense says all four people aboard the Griffin training helicopter got out safely after the aircraft developed a "technical issue" on Tuesday. It says that "subsequently the aircraft caught fire."

Photos taken by hikers showed a thick plume of smoke rising from Yr Aran, a peak in the Snowdonia range in north Wales.

Police and the ambulance service said they were at the scene.

The mountains are close to RAF Valley, an air base where Prince William was posted between 2010 and 2013 as a Royal Air Force search-and-rescue pilot.