near Okehampton, at about 03:45 BST and a major incident was declared. A Royal Navy spokesperson said "it is with deep sadness that we can confirm three members of the Royal Navy have died during a helicopter training exercise". They added: "The families of the service personnel have been informed and have requested a period of grace before further details are released. Our thoughts and sympathies are with their families and friends at this sad time". Head of the Navy, General Sir Gwyn Jenkins, said in a statement: "I know this will come as a huge shock to all in our naval community, and my deepest condolences go out to the families, friends and loved ones impacted by this tragedy". Images from the scene show the front of the aircraft, a Merlin Mk4 helicopter, had been destroyed. Military helicopters often train in the area around north Dartmoor, which lies between the Royal Navy's air bases at Yeovilton in Somerset and Culdrose in Cornwall. The scene of the crash is also close to Okehampton battle camp, a military facility on the edge of Dartmoor which has been used for training Merlin helicopter crews from the Commando Helicopter Force. The BBC understands the helicopter was based at RNAS Yeovilton. The Merlin helicopter is primarily used for anti-submarine warfare and can also be used for search and rescue, cargo transfers and maritime patrol, according to the Royal Navy's website. (BBC)