An "improvised" gun and bullets were seized after raids at two homes in Limerick city.
The suspected homemade firearm and ammunition were recovered after properties in the Moyross area were searched at around 11am on Wednesday.
No one was arrested following the operation which targeted suspected criminal activity in the county.
A garda spokesman said: "At 11am Detective Gardaí from the Henry Street District, assisted by the Armed Support Unit, carried out two searches at houses in the Moyross area.
"During the course of one of the searches at a vacant house, Gardaí discovered what is believed to be an improvised firearm and ammunition.
"It was made safe by Gardaí and will now be sent for analysis. The Divisional Scenes of Crime Unit also attended and carried out a technical examination of the house.
"No arrests have been made and the investigation is ongoing."
