Two men arrested following the discovery of a massive bomb destined for Northern Ireland were last night still being interrogated by police in the Republic.
The suspected dissident republicans, aged 50 and 25, were arrested following the discovery of bomb-making components and fertiliser in Monaghan on Saturday.
Gardai said the components and the 200kg of fertiliser seized near the border were sufficient to make a large bomb.
The men, not from Northern Ireland, were stopped in the town in the early hours of Saturday and are now being held under Section 30 of the Offences Against the State Act in a Monaghan police station.
Their period of detention was extended early on Sunday. Detectives can hold them for up to three days.
The arrests were made by gardai targeting dissident activity in the border area.
Gardai, who stopped and searched a van where the material was found, said: "During the course of searching this van, components for bomb making, subject to forensic analysis, were discovered by the gardai.
"These items and the van were seized for technical examination."
It is thought the weekend Garda operation may have thwarted a possible attempt by dissident republicans to place a bomb-trap near a security forces' base in south Armagh.
The bomb find follows a series of security alerts in Northern Ireland over the past week, the most serious of which was a device addressed to Secretary of State Theresa Villiers and uncovered at Stormont.
It also followed similar attempts on the lives of PSNI Chief Constable Matt Baggott and one of his senior commanders.
SDLP representative Dominic Bradley said he had little doubt the huge bomb was on its way across the border in to Northern Ireland.
"When you hear of this discovery you have to arrive at the inescapable conclusion that these materials were destined for the North," he said.
"The reaction must be one of relief the Guards have been successful in thwarting this attempt.
"If all this material had not been set to be part of one bomb then there certainly enough for a series of bombs."
The chairman of Stormont's justice committee, DUP MLA Paul Givan, said the find was "deeply worrying".
He said the PSNI had had a "fair degree of success" in tackling recent dissident threats in Northern Ireland, but would be examining whether they could cope with bomb threats on this scale.
"Certainly we will be working with police to ensure they have enough resources to deal with a threat such as this," he said.
"It is a timely reminder there are people determined to wreak havoc in our community. There is absolutely no doubt this material would have caused devastation and carnage in some town centre. Certainly I am thankful that the bomb has been found and pay tribute to the authorities."
Justice committee chairman Paul Givan