Detectives in Newry and Mourne, supported by local officers in South Armagh, raided premises on Mountain Road on Wednesday.
They recovered two vehicles, believed to be stolen, and two suspected firearms.
Two quads have also been seized.
Police say inquiries are ongoing.
Newry and Mourne Area Commander, Chief Inspector Davy Beck, said: "The hard work and commitment of local officers has resulted in dangerous weapons being taken out of circulation, making Newry and Mourne a safer place to be.
"This search and the seizure of vehicles should send a clear message that there is no hiding place for criminals in Newry and Mourne."
CI Beck added: "I would like to thank the local community for their support and patience during this operation.
"This again demonstrates how much more successful we are in tackling crime when we work together."