The Special Criminal Court has refused bail to three men charged in connection with the discovery of a massive bomb near the border last month.
The court also refused bail for a fourth man charged with membership of an illegal organisation who was arrested in connection with the same incident.
The court heard that gardaí believe the four men were part of a Continuity IRA group preparing a bomb.
Mr Joseph Fee (39), of Blackstaff, Carrickmacross, Co Monaghan, Mr Seamus Mc Kenna (48), of Marian Park, Dundalk, Co Louth and Mr Gregory Trainor (37), of Culdee Road, Armagh are each charged with the unlawful possession of an explosive substance, ammonium nitrate and sugar, on June 13th, 2003 at Thornfield, Iniskeen, Co Louth.
Mr Eamonn Mathews (24), of Dublin Road, Killeen, Newry, Co Down is charged with membership of an illegal organisation styling itself the Irish Republican Army, otherwise Óglaigh na hÉireaan, otherwise the IRA on June 12th.
Detective Superintendent Diarmuid O'Sullivan, who opposed bail, said Mr Fee, Mr Trainor and Mr McKenna were "caught red-handed" in the process of making a bomb.
He said that Mr Trainor and Mr McKenna were arrested while mixing ground down fertiliser with sugar. Mr Fee was arrested 100 yards from the farm where the explosives mixture was being mixed and gardaí found a bucket with a mixture similar to the mix found at the farm in his van. They also found timing devices and gloves.
Det Supt O'Sullivan said that he believed the men would continue to be actively involved with the Continuity IRA and would not stand trial if released on bail.
He said that gardaí found a white van in a shed at a farm at Iniskeen in which they found a bag containing 500 kilos of home made explosives made from ground down fertiliser and sugar.
They also found a electric mixer close to the rear of the van and four bags of icing sugar weighing 300 kilos and a bag filled with diesel.
Refusing bail for all four men , Mr Justice Richard Johnson, presiding, said the court accepted the evidence and refused bail because it believed it was reasonably necessary to prevent the commission of further serious offences by the accused.
All four men were remanded in custody until July 22nd next.