Police investigating the bomb attack at Strand Road police station in Derry ten days ago have discovered guns and ammunition following a number of searches.
The PSNI says a replica AK47 rifle, a .22 rifle, over 100 rounds of ammunition, balaclavas and a mobile phone have been removed for forensic examination.
A 53-year-old man is being questioned.
Earlier, a man was remanded in custody at Derry Magistrates Court.
Philip O'Donnell, 42, from Baldrick Crescent in the Rosemount area of Derry faced a total of 12 charges when he was brought before the court.
Mr O'Donnell was accused of causing the explosion, possessing explosives and a firearm, hijacking a taxi and falsely imprisoning a taxi driver.
He was also charged with being a member of an illegal organisation, Óglaigh na hÉireann. He was remanded in custody.
During the incident, a taxi driver was forced at gunpoint to drive to the police station after a device carrying 90kg (200lbs) of explosives was placed in his car.
Police were still clearing people from surrounding buildings, including a fast food takeaway, when the bomb went off.
Nobody was injured but a number of buildings in the area were damaged, including a nursing home and apartments.
