Two more people were taken into custody yesterday in connection with Sunday's arms seizure in Co Tipperary.
A husband and wife in their early 40s were arrested at a house on the outskirts of Tipperary town and taken to Cahir Garda station, where a third man has been detained since Sunday.
The three are being held under Section 30 of the Offences Against the State Act.
Follow-up searches of the house where the couple were arrested and surrounding areas were continuing last night.
The discovery of home-made rockets and Semtex explosive on Sunday has been linked to the Continuity IRA, the only republican paramilitary group which is currently not on ceasefire.
The seizure was made at a checkpoint outside Cahir when gardai stopped a commercial van heading in the direction of Limerick. The driver of the van saw the checkpoint, jumped from the vehicle and attempted to run from the scene, but was pursued by gardai and arrested.
Garda technical experts were yesterday continuing their examination of the weapons found in the back of the van.
These included two drogue bombs which were primed and contained Semtex, hand grenades, projective grenades and other bomb components.
The drogue bombs were designed to be dropped on their target from a height, and have armour-piercing capability.
Further searches of the area where the couple were arrested yesterday are likely today, but no additional arms had been discovered last night.
Gardai have until this evening to charge or release the first person taken into custody, a 39-year-old Limerick man.
The Garda national surveillance unit had been monitoring the activities of dissident republicans in the Limerick area before Sunday's arms seizure.
It was believed the dissident group planned to take weapons from Provisional IRA arms dumps in the south-west, and move them to Northern Ireland for possible attacks on the security forces.
Sunday's haul was the first significant arms seizure in the State since last October, when there were successful raids at a purpose-built bunker in Co Meath, a forest in Co Wexford and a house in west Dublin.
The last two were linked to the Continuity IRA which was set up in the early 1990s by members connected with the splinter political group, Republican Sinn Fein.
