Two men and two women were arrested in a car carrying a suspected firearm.
The four were stopped on Flagstaff Road area of Newry yesterday evening (Saturday).
Officers received a report of a number of individuals in a blue car behaving suspiciously at Brogies Road at around 7pm.
Police attended the area and noted a vehicle, with a number of people on board, which matched the description received, at Flagstaff Road.
A bag was located near the car containing a suspected firearm and a number of other items.
The men aged 23 & 24 and the women aged 19 and 29 were arrested on suspicion of a number of offences including carrying a firearm with intent to commit an indictable offence, going equipped for burglary and possessing an article with a blade or point.
All four have since been released on bail pending further police enquiries.
Detective Inspector David Henderson has appealed for anyone with any information which could assist police with their enquiries to contact detectives at Ardmore using the non-emergency number 101 or Crimestoppers anonymously on 0800 555 111.