Gardaí targeting dissident republicans have uncovered a significant cache of explosives and arms along the border, in the second linked operation since the start of February.
The haul comprised two firearms, believed to be rifles, a significant quantity of ammunition, and around a quarter of a kilo of plastic explosives, along with a detonator.
While not a large quantity of explosives, sources said it could be used in an attack on a car or something similar, and the presence of a detonator meant it was ready to be deployed.
The operation, which concentrated on lands around Omeath, Co Louth, was conducted on Thursday by officers from specialist anti-terrorism and firearms units, and involved gardaí from the Louth Division.
Gardaí suspect that the firearms, ammunition, and explosives were hidden there in relatively recent times.
A controlled explosion of the explosives and the detonator was conducted by an Army bomb squad.
The find is part of an ongoing operation against “dissident republican groups”, with the New IRA considered to pose the biggest threat to security forces north and south.
Fears have been expressed, including by Garda Commissioner Drew Harris, that dissidents plan to exploit Brexit, particularly if it involves a hard border.
In January, a car bomb exploded outside Derry courthouse, an attack that was blamed on the New IRA.
No one was injured, but the bomb went off shortly after a group of young men had walked past the vehicle.
A Garda statement said the operation involved gardaí from the Louth Garda Division, Special Detective Unit, and from Special Tactics and Operations Command.
The statement said: “During the operation, gardaí recovered a quantity of explosives, two firearms, and a sizable quantity of ammunition of various calibres.
An explosive ordnance disposal unit of the Irish Defence Forces later visited the site and some of the material was later destroyed by a controlled explosion.
In its statement, the Defence Forces said an army bomb disposal team was tasked to the scene, where gardaí had found weapons and ammunition along with “a small quantity of plastic explosives and a detonator”.
“The team arrived on scene at 6.35pm,” it said.
“On arrival, a cordon was established.
“The quantity of explosives and the detonator were disposed of and the scene was declared safe at 8.25pm.”
In the first operation, on February 1, gardaí uncovered a mortar tube and around 1,000 rounds of ammunition in separate hides some 6km outside Omeath.
It is thought that the tube and the ammunition had been stored there for at least a year and was linked to dissident groups
Soon after he was appointed last September, Commissioner Harris, the former deputy chief constable of the PSNI, said that dissident republicans remained the “greatest threat” on the island.
He subsequently told the Oireachtas Justice Committee that he feared a hard border would be a “rallying call” and an “emotional driver” for dissidents.