The Ministry of Defence (MoD) has confirmed that five Royal Marines have been charged with murder in relation to an incident in Afghanistan in 2011.
Seven marines were initially arrested and the MoD said Royal Military Police (RMP) had arrested two more marines on suspicion of murder, taking the total number of arrests to nine.
Four have since been released without charge, pending further inquiries.
A statement from the MoD said: "The RMP has referred the cases of the remaining 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."
The soldiers, believed to be members of 3 Commando Brigade, were arrested in connection with an incident which occurred while they were based in Helmand last year.
A statement on the MoD's website described the incident as "an engagement with an insurgent", adding, "no civilians [were] involved".
The tour called, Operation Herrick 14, was the unit's fourth and saw the force score notable successes in capturing explosives from the Taliban.
The arrests are thought to be the first time UK servicemen have been held on suspicion of such charges during the conflict in Afghanistan.