Gardaí are now appealing for witnesses.
Gardaí have arrested two men and seized a firearm during an operation on Wednesday (13 October) at around midday in Finglas, north Dublin.
In a statement, Gardaí said a vehicle was abandoned on the N2 underpass at the M50 junction heading towards the city centre.
In a follow-up search, two men - aged 33 and 20 - were arrested a short distance away and a firearm was recovered.
Both men were arrested at the scene and taken to Finglas Garda station.
Gardaí are now appealing to anyone who may have witnessed the car, a black Volkswagen Golf, that was abandoned on the underpass on the N2 to come forward.
Any road users who were travelling along the N2 towards the city centre between 11.45am and 12.15pm on Wednesday and who may have camera footage, including dashcam footage, is asked to make it available to Gardaí.
Anyone with any information is asked to contact the Garda Confidential Line on 1800 666 111 or any Garda station.
Investigations into the incident are ongoing.