Nine people were arrested after armed detectives searched a house in Tallaght in south west Dublin last night, it emerged today.
The eight men and one woman, aged between 19 and 43 years, have been detained at several Garda stations.
They were arrested after a search of a house on Cushlawn Drive at about 7pm last evening and are being questioned under Section 30 of the Offences Against The State Act.
"The search was an intelligence-led operation carried out by members of the Special Detective Unit and Emergency Response Unit," a Garda spokesman said.
A technical examination of the house is continuing.
It is believed that the operation involved members of a special unit investigating a spate of grenade and bomb attacks in Dublin and Limerick in recent months.
The suspects can be detained for a maximum period of 72 hours.
In June, 100 residents of the Coombe area of Dublin were evacuated from their homes after a grenade was thrown at the wall of a house.
Gardaí believed the attack was linked to a feud between a former INLA member and criminal rivals in the area.
Two days earlier, a pipe bomb was thrown from a car in the Mulhuddart area of west Dublin.
In another incident, pipe bombs found on the Co Limerick/Co Tipperary border were believed to be linked to Limerick City's feuding gangs.