The men can be held for up to three days
Two men have been arrested as part of an investigation into the activities of dissident republicans.
The pair, both aged in their 30s, were detained during operations in Meath and Dublin on Thursday.
One man was arrested when gardaí searched a house in Meath - the second man was arrested during a search of a house in west Dublin.
They are both being detained under Section 30 of the Offences against the State Act in a west Dublin garda station.
They can be held for up to three days.
The operation was led by members of the Special Detective and Emergency Response Units.
Gardaí say the investigation is ongoing.