A 34-year-old man is being questioned after a six-hour armed stand-off at an apartment complex.
The man, who was seen carrying a handgun, was arrested just after 11pm on Tuesday after barricading himself into the flat near the quays in Waterford city.
He had been alone in the apartment.
At one stage during the stand-off the man took to the roof of the four-storey building and was seen brandishing the weapon.
Armed gardai and trained negotiators were called in at about 5.30pm and streets around Penrose Lane were cordoned off as officers tried to talk the man down.
Residents in the apartment block were also evacuated.
The man is being held under Section 30 of the Offences Against the State Act at Waterford garda station.
The weapon was taken away for ballistic tests.