Gardai investigating the activities of the republican terrorist group, the "Real IRA", are expected to bring charges against at least one of the four men arrested on Sunday at Bettystown, Co Louth.
One man is already on bail facing a charge of membership of the illegal organisation. It is likely his bail, under which conditions included that he avoid contact with members of any illegal group, may be revoked at least temporarily.
Garda sources said that a meeting was taking place at Bettystown on Sunday afternoon. Members of the Garda's Emergency Response Unit broke in on it.
The four men, three from Co Louth and one from Dublin, were arrested under the Offence Against the State Act, which allows for their detention for up to three days without charge.