Detectives investigating the murders of two British soldiers at Massereene Barracks in Co Antrim in March have arrested a 47-year-old man.
The man was arrested in the Belfast area this afternoon and was taken to the PSNI's serious crime suite in Antrim.
The suspect is being questioned about the murders of sappers Patrick Azimkar, 21, from London, and Mark Quinsey, 23, from Birmingham.
The man is also being quizzed about the attempted murder of five people in the same incident.
Leading dissident republican Colin Duffy, 41, from Lurgan, Co Armagh, has been charged with the murders.
Brian Shivers, 44, from Magherafelt, Co Derry, has also been charged over the killings. However, he was granted bail because of his illness.
The soldiers were the first to be murdered in Northern Ireland in 12 years. Their deaths were followed two days later by the Continuity IRA murder of policeman Stephen Carroll in Craigavon, Co Armagh.
He was the first policeman to be murdered in Northern Ireland since 1998.
