A massive 600lb bomb has been made safe in South Armagh in Northern Ireland.
British Army experts also discovered a command wire which snaked across the border into County Louth.
Ireland's Justice Minister Dermot Ahern, who is himself from County Louth, slammed the militants responsible as "anti-republican."
"We spent years negotiating with the British to demilitarise the border. Their actions are anti-republican," he said today.
The bomb was discovered after "dissident republicans" phoned an Irish newspaper to say they had planted a bomb.
Several families had to leave their homes in the Forkhill area while the bomb was being made safe.
The Police Service of Northern Ireland said the bomb was connected to a firing point in County Louth where gardaí (Irish police) carried out a similar security operation.
Northern Ireland First Minister Peter Robinson said the bomb "shows that there are evil people out there still prepared and with the equipment to take life in Northern Ireland.
"I am delighted it has been defused, but it does show that there is still a very real and present danger. It indicated there are people who still have to be dealt with by the PSNI."
Security experts say that the device would have caused a bigger explosion than the Omagh bombing.