A Royal Marine trainee has collapsed and died on an exercise in Dartmoor, the Ministry of Defence (MoD) has said.
The man - who has not yet been named - was taking part in a 30-mile march across Dartmoor on Thursday when he died.
The cause of death is currently unknown, an MoD spokesperson said.
He was based at the Commando Training Centre at Lympstone, Devon.
The so-called "30-miler" march is one of the last major tests undertaken by trainees as part of the 32-week Commando course.
Recruits must navigate the route themselves and complete it within eight hours while carrying safety equipment.
An MoD spokesperson said the man's name and details were not being released at the request of his family.
This incident is being investigated and the thoughts and sympathies of the Naval Service are with the family and friends of this man.
A former Royal Marine from Somerset has said it was an honour to serve with Prince Harry.
Ben McBean from Plymouth, who lost an arm and a leg in a blast in Afghanistan, was dubbed a hero by the prince, who has announced that he's leaving the armed forces later this year.
Servicemen and women who died during the Afghanistan campaign and veterans have been remembered at a service of commemoration today.
The royal family, civil dignitaries and government leaders all attended the ceremony at St Paul's Cathedral, along with serving personnel, veterans and families.
Warrant Officer Matt Tomlinson is a Royal Marine from Torpoint in Cornwall. He was awarded the Military Cross for saving the lives of colleagues during a fierce firefight in Afghanistan .
The lead vehicle was blown up by an IED and Matt braved incoming rocket-propelled grenades and small arms fire to help rescue the seriously injured driver.
Around 40 children have been put through their paces this week by Royal Marines from 42 Commando.
All of the youngsters are members of Her Majesty's School Heroes, a support group for children of service men and women.
The workshop, at Bickleigh Barracks in Plymouth, gave them the chance to do commando-style challenges.
I think it's really important for the children of the servicemen and women to sort of see what their mums and dads get up to on a day to day basis.
There's not that much opportunity really for them to see that and I think it is really interesting and rewarding for them to do that and I think HMS Heroes gives them that platform.
Some famous faces have appeared on a video wishing the Royal Marines a happy 350th anniversary.
They include The Prime Minister, Bear Grylls, Harrison Ford, Ross Kemp, Caroline Quentin, Tom Hardy and Henry Cavill.
You can watch the video here.
We're used to seeing them either training or in action in some of the world's trouble spots, but today marines from 42 commando, based in Plymouth, had a very different role.
They were providing sentries outside Buckingham Palace - and that meant changing the guard in front of thousands of tourists. Bob Constantine reports:
Royal Marines from Plymouth are helping guard Buckingham Palace.
Men from kilo company, Four-Two Commando, have swapped their usual camouflage for full dress uniform as they patrol the railings outside the royal residence.
It's to mark the corps' 350th anniversary and is only the fourth time in a hundred years they've taken on the ceremonial duties.
The Royal Marines of Taunton-based 40 Commando have been flexing their muscles on exercise in Cornwall.Read the full story ›
A former Royal Marine from Taunton, who was found guilty of murdering an injured insurgent in Afghanistan, has lodged an appeal application in a bid to challenge his conviction.
39 year old Sergeant Alexander Blackman was jailed for a minimum of 10 years in December.