A suspected mortar tube and a "substantial quantity of ammunition" have been recovered by police close to the Irish border in County Louth.
Gardaí (Irish police) and the Irish army searched land near the village of Omeath on the Cooley peninsula.
In a statement, the Gardaí said the operation was "targeting the activities of dissident republican groups".
The searches began on Friday morning and ended on Saturday. No arrests have been made.
The operation was led by Garda Special Detective and Emergency Response Units.
Irish army explosives experts were also involved.
The suspected mortar tube will be examined by Garda ballistics experts.
Irish national broadcaster RTÉ reported that the haul is being described as "significant".