A man has been arrested in connection with the murder of two soldiers in Antrim last month.
The 19-year-old was detained in the Bellaghy area of south Londonderry at about 0700 BST on Thursday.
Sappers Mark Quinsey and Patrick Azimkar were shot dead at the gates of Massereene Barracks as they collected pizzas from delivery men.
Last week Colin Duffy from Lurgan appeared in court accused of their murders.
The man detained on Thursday is also being questioned about the attempted murder of five other people, including two pizza delivery men, in the attack on the County Antrim barracks.
On 26 March six suspects in the murders, including Mr Duffy, were released by the High Court after a legal challenge to their detention.
Mr Duffy was freed but re-arrested at Antrim police station a short time later and charged the following day.