A man in his 20s was arrested and a loaded firearm recovered at Connolly Station in Dublin this afternoon.
Gardaí boarding the 3:20pm train from Connolly to Belfast and arrested the suspect.
The man is being detained at Store Street Garda Station.
The train was delayed for 15 minutes while the operation was carried out.
The arrest came as part of an ongoing investigation into organised crime, according to gardaí.
This evening, gardaí said a woman was arrested at Dublin Airport as part of follow-up searches.
She is also being held at Store Street Garda Station.
