The arrests by the Royal Military Police relate to a killing that happened after “an engagement with an insurgent”, the Ministry of Defence (MoD)said.

No civilians were involved in the incident, which is understood to have taken place in the Nad Ali district. The arrests were made at around 4.30pm on Thursday, according to Sky sources.

The MoD said: “The investigation will now be taken forward and dealt with by the Service Justice system.

“These arrests demonstrate the Department and the Armed Forces’ determination to ensure UK personnel act in accordance with their Rules of Engagementand our standards.

“It would be inappropriate to make any further comment while the investigation is under way.”

As the alleged incident took place outside the country, it is understood the Royal Marines accused will not be subject to UK courts.

The rules of engagement, largely derived from the Geneva Convention, dictate under what circumstances British troops are allowed to open fire in direct contact or to prevent attacks.

source:                                    http://news.sky.com/story/996601/seven-royal-marines-held-over-afghan-murder