A MoD spokesman said:
The Royal Military Police (RMP) has arrested two further Royal Marines on suspicion of murder in relation to an incident alleged to have taken place in Afghanistan in 2011, taking the total number arrests to nine.
Four Marines have since been released without charge pending further enquiries.
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.
It would be inappropriate to comment further on this ongoing investigation.