Connolly station had to be evacuated yesterday after a man arrived on a train with a suspected gun.
Gardaí say that shortly after 6.20pm they got a report of a passenger onboard a commuter rail service from Sligo arriving into the Dublin station, who had been spotted with a suspect firearm.
A large scale response, including teams of armed gardaí, were deployed to the scene and the station was evacuated.
A security sweep was carried out and a man in his 50s was arrested. He's being held under Section 30 of the Offences Against the State Act, 1939 at a Garda Station in the Dublin Region.
The station was declared safe and reopened shortly before 7.30pm.
The suspect firearm was seized and will undergo a full technical exam.
Anyone with information is asked to contact Store Garda Station on 01 666 8000, the Garda Confidential Line on 1800 666 111 or any Garda station.
Fake news
Meanwhile gardaí say they are aware of commentary around the incident being shared online which it says contains misinformation, disinformation and fake news.
Officers are appealing to the public to independently verify any information that is shared on social media or sent through message sharing apps.
