Police presented Sunday the rifles and ammunition found at a home belonging to a member of the Revolutionary Self-Defense terrorist group.
"Fortunately, our intervention was timely…What is frightening, is the amount of explosives they possessed," Lefteris Hardalias, leadse of the police's Counter-Terrorism Agency.
Officers arrested two men and a woman allegedly implicated in terrorism activities and detained another 15 people on Saturday.
Police said they raided 13 houses, seizing five AK-47 assault rifles, a submachine gun, two pistols, detonators, dynamite, TNT and grenades.
Two male suspects, aged 41 and 43, have been linked to a robbery at a betting shop in the Athens suburb of Holargos in October. The third suspect, a 39-year-old woman, was detained for violating firearms laws. She is believed to be the partner of another suspect, a 46-year-old anarchist, who remains at large.