Two men are to appear at the District Court on charges relating to the possession of a firearm and ammunition.
The men were questioned by gardaí in Co Louth as part of an ongoing investigation into the sale and supply of guns in the State.
The men, along with another man and a woman, were arrested following the seizure of a firearm, ammunition and cash when two cars were stopped and searched in the Castlebellingham and Haggardstown areas outside Dundalk on Thursday night.
The four suspects, aged between 20 and 30, were taken to Garda stations in Dundalk and Carrickmacross for questioning.
The man and the woman who were questioned at Carrickmacross Garda station were released yesterday evening.