Gardai are today quizzing two men under anti-terrorism laws after they uncovered a cache of mortar bombs and rockets.
The 20 mortars and 20 rockets were found in two separate locations near Athy, Co Kildare, one in undergrowth beside the Royal Canal.
Earlier police detained two men in an operation based in the counties of Kildare, Laois and Carlow.
The pair held for questioning were detained by members of the Garda special detective unit in the neighbouring Co Kildare towns of Naas and Newbridge.
The moves also involving the Garda special branch and air support officers using specialist search equipment marked the latest in a series of swoops aimed at hardline republicans linked to two paramilitary groups, the Real IRA and the Continuity IRA.