Firearms, ammunition and drugs were seized by gardaí in Limerick yesterday following searches of more than 40 houses in the Southill area of the city.
The national Garda air support unit and the Garda dog unit assisted up to 50 local gardaí in the major search operation.
The planned searches commenced at 2.30pm and by early evening at least four firearms including a handgun, a quantity of cannabis and a "significant" amount of ammunition had been seized, according to Garda sources.
A Garda spokesman confirmed that at least 40 properties and an area of open ground were searched during the operation.
It is understood that most of the searches took place in the Keyes Park area of Southill. However, a number of properties in other Southill estates were also searched. A man in his late teens was arrested yesterday evening as part of the operation and he was being questioned last night at Roxboro Garda station.
Tensions have been running high in the Southill area in recent weeks as gardaí try to deal with a spate of shootings and violent incidents linked to a new feud, which has broken out in the area.
Yesterday's operation took place just 48 hours after a gunman opened fire on two gardaí who were on patrol in an unmarked Garda car in the O'Malley Park area of Southill on Sunday night.
A 37-year-old man, described as a leading member of one of the factions at the centre of the new feud, was arrested a short time later but he has since been released without charge. A senior Garda source said that yesterday's search operation had been planned prior to the shooting.