Two pipe bombs, gunpowder, a large quantity of ammunition, cocaine worth €1,100 and €500 worth of suspected Alprazolam tablets have been seized by gardaí in Co Louth.
The haul was uncovered during a search of a house in Drogheda town at about 11pm on Thursday.
A number of homes in the area had to be evacuated during the operation.
Army technical experts safely removed the two improvised explosive devices, and other material believed to be used in the manufacture of explosives, for further examination.
The operation only ended at 5am on Friday, but the scene is still being preserved for further forensic examination.
Two men have been arrested and held for questioning – one in his early 40s and one in his mid-50s.
Gardaí say the search was related to Operation Stratus, which is aimed at disrupting organised crime.