A teenager has been arrested after a handgun was recovered, gardai said.
The suspect, in his late teens, was found with the pistol at East Road in the East Wall area of Dublin at around 2.30pm on Saturday.
He is being held under section 30 of the Offences Against the State Act at Store Street Garda station.
The operation was carried out by local detective and drug units.
Gardai described the operation as intelligence led.