A third man was arrested tonight by police investigation the murder of a prison officer in Northern Ireland.
The suspect, 29, was detained in the Irish Republic by police.
Earlier, two other men including prominent dissident republican Colin Duffy were arrested in connection with David Black's murder
Mr Black, 52, was gunned down during a high speed ambush yesterday on a motorway as he drove to work at Maghaberry high security prison.
His killing has prompted condemnation from across Britain and Ireland and police have blamed it on dissident republicans.