Three men are still being questioned in connection with the murder of Northern Ireland prison officer David Black.
The 52 year old, father of two, was shot dead as he drove to work on the M1 motorway in Lurgan last Thursday.
Two men are being questioned in Armagh, and one man who was arrested in Leitrim last night is being questioned in Carrick on Shannon.
There’s been widespread condemnation of Mr Black’s killing, with US Secretary of State Hillary Clinton describing the attack as "senseless and cowardly".
