Britain's Ministry of Defense says it has arrested seven Royal marines on suspicion of murder in relation to an incident in Afghanistan in 2011.

The defense ministry said Thursday the incident did not involve any civilians, but followed "an engagement with an insurgent."

It added that the seven were arrested Thursday by Royal Military Police.

The Ministry of Defense did not name the marines or give any further details, saying only that the investigation will now be taken forward by the Service Justice System.