Five Royal Marines have been charged with murdering a Taliban fighter over an "incident" which took place on the battlegrounds of Afghanistan last year.
The Ministry of Defence has confirmed that the men, believed to be members of 42-Commando, which is based at Plymouth's Bickleigh Barracks, would appear before a court martial.
By last night an online campaign of support for the men had attracted more than 40,000 internet 'likes' on the Facebook website.
Inspirational former Royal Marine Mark Ormrod, who lost both legs and an arm when he trod on a Taliban landmine on Christmas Eve 2007, aired his feelings on Twitter.
He re-tweeted a message to his 4,500 followers which read: "PLEASE RT (re-tweet) and show your support for the 5 royal marines charged with murder whilst serving our country.. FREE THE FIVE."
A total of seven men were arrested late on Thursday as part of an investigation by the Royal Military Police (RMP).
On Friday night and Saturday morning, a further two men, believed also to be Royal Marines, were arrested.
The four men who were not charged were released, pending further enquiries.
A spokesman for the Ministry of Defence said: "The RMP has referred the cases of five Royal Marines to the independent Service Prosecuting Authority (SPA).
"Following direction from the SPA these marines have now been charged with murder and they remain in custody pending court proceedings.
"It would be inappropriate to comment further on this ongoing investigation."
The incident in the spotlight has been described as "an engagement with an insurgent" with no civilians involved.
The Marines are understood to be members of Plymouth-headquartered 3 Commando Brigade, which last summer led the British mission in the Helmand region of Afghanistan.
The Royal Marines are understood to have been arrested so long after the incident because video footage was discovered on the laptop belonging to a serviceman who was being questioned by civilian police on an unrelated matter. The clip appears to show members of a Royal Marines patrol standing around an injured Taliban fighter as he lies on the ground of a compound.
The clip ends before anything happens but it is understood that the man died.
During a six-month tour of duty, which lasted from April to October last year, seven servicemen from 3 Commando Brigade were killed in action, all from 42 Commando.
The tour, Operation Herrick 14, was the unit's fourth and saw the force score notable successes in capturing explosives from the Taliban.
The rules of engagement, largely derived from the Geneva Convention, dictate under what circumstances troops are allowed to open fire, whether that is to prevent an attack by the enemy or in direct contact.
The arrests are thought to be the first time UK servicemen have been held on suspicion of such charges during the conflict in Afghanistan.
Defence Secretary Philip Hammond said he was determined that the rules of engagement were followed in Afghanistan.
He told the BBC's Andrew Marr Show: "Everybody serving in theatre knows the rules of engagement, they carry cards in their uniforms with the rules on them in case they should need to remind themselves.
"I can't comment on the specifics of this case.
"We are very determined that rules of engagement will be followed, that any abuse will be dealt with through the normal processes of service justice and that is happening now."
However, since news of the arrests broke there has been a powerful backlash against the Government on social networking and unofficial military websites.
One social networking site Twitter hashtag supportthe5royalmarines was a prominent thread over the weekend with many expressing disgust at the charges against the Marines.
A Facebook campaign initially aimed at supporting the seven Royal Marines initially questioned was re-titled to reflect the five who were actually charged. By last night, the page had amassed nearly 40,000 "likes".
The person who set up the page claims to be serving in the British Armed Forces and deploying to Afghanistan "in the next few days", although he says he is not a Royal Marine.
In the information section about the page, he wrote it was done to show support for those "arrested for murder for an event which happened in Afghanistan 2011 where no civilians where injured..."
One member called Wendy Britton, who says she is the mother of a Royal Marine, wrote: "I cried for these seven poor Royals for being punished for doing their job."