Six men with suspected IRA links were being questioned by gardaí today after a raid by officers in Bray, Co Wicklow.
Five of the men were arrested in Bray by a Special Branch officer who saw them behaving suspiciously at Corke Abbey. A sixth man was arrested later in South Co Dublin.
Four of the men are being held at Bray Garda Station, while two are being held at by gardaí at Shankhill.
The operation uncovered replica police uniforms, two-way radio sets, pick-axe handles, sledgehammers, plastic ties, balaclavas and gloves.
The men in custody are being held under Section 30 of the Offences Against the State Act, which permits gardaí to hold them for 72 hours before being either charged or released.
At least three of the group were reckoned to have connections with the Provisional republican movement and police believe they were plotting a major crime at the time of the raid.
It was not clear whether the men were planning an action authorised by the leadership of their organisation or operating independently, but the development was being seen as adding to current pressure on Sinn Féin.