Firearms, including a submachine gun, were seized by gardaí investigating organised crime activity in north and west Dublin, which led to two murders over Christmas.
A sawn-off shotgun and a quantity of ammunition were also seized.
Two people, a man and a woman, are also still being questioned following the seizure of a loaded handgun on Friday.
This latest seizure is part of garda investigations into organised crime and feuding criminal gangs in north and west Dublin following the murders of two men over Christmas.
The gunman, 26-year-old Tristan Sherry died in an attack after he shot Jason Hennessy senior at Browne's Steakhouse in Blanchardstown on Christmas Eve.
The 48-year-old subsequently died in hospital.
At around 3.30pm on Friday armed detectives from Blanchardstown and the Emergency Response Unit stopped a car on the Old Navan Road and seized a loaded handgun and ammunition.
They suspect the weapon was being moved in preparation for a shooting.
A man in his 20s and a woman in her 30s were arrested and remain in custody.
They are being detained under Section 30 of the Offences Against the State Act and can be questioned for up to 72 hours.
Follow up searches were carried out on Friday and yesterday at two houses in Dublin and gardaí from Blanchardstown recovered a submachine gun and a sawn-off shotgun.
These have been taken for ballistics tests and forensic examination.
Seven people are currently before the courts in connection with this investigation.
