The raid took place yesterday afternoon at an undisclosed location.
Three men have been held overnight after being arrested in the midlands.
It's after a Garda operation targeting dissident republicans.
The Special Detective Unit - backed up by armed officers from the Emergency Response Unit - launched the raid yesterday at an undisclosed location in the midlands.
Gardaí say the searches were targeting dissident republicans.
They arrested three men, two aged in their forties and one in his fifties, under Section 30 the Offences Against the State Act.
A search continued at the scene until late yesterday evening - with gardaí saying it remains a "live operation".
The three men were taken to Dublin, where they're being held at separate garda stations.