Five members of Republican Sinn Fein's ardchomhairle are among those still being questioned by detectives under Section 30 of the Offences Against the State Act. Seven men were arrested as they made their way home from the party's ardfheis in Drogheda, Co Louth, on Sunday.
They are being held in Trim, Navan, Kells and Ashbourne Garda stations. Og O Bradaigh; ardchomhairle members , Mr Mick McManus from Co Fermanagh, and Mr Eamon Larkin from south Armagh; and party member , Mr Joe Malone from Westmeath. In associated raids, gardai visited a home Og O Bradaigh and Mr O'Neill's home and pub in in Dublin and business premises in Donegal. A computer was seized.
The men can be held for 72 hours.
It is understood they have been asked to give detailed accounts of their movements on certain dates up to four years ago.
Failure to do so could be used under the legislation introduced after the Omagh bomb as corroborative evidence concerning charges of membership of an illegal organisation.
The Republican Sinn Fein president, Mr Ruairi O Bradaigh, claimed the security operation was aimed at silencing political critics of the Belfast Agreement. "This is a blatant attempt at intimidation," he said.
Security sources say Republican Sinn Fein is the Continuity IRA's political wing, a claim the party denies.