Police in Northern Ireland have confirmed that a van at the centre of a major security alert close to the border yesterday contained a 'very substantial' bomb.
A number of controlled explosions were carried out on the vehicle found at a section of the main road between Belfast and Dublin, near Newry, after which officers confirmed a viable bomb had been found.
It was contained in a wheelie bin packed with 500lbs of homemade explosives and could have been destined for an attack on a town centre, according to the PSNI.
Detectives believe the vehicle, found near Newry at an underpass beneath the
main A1 route between Belfast and Dublin, was abandoned because of the presence
of a police checkpoint.
"Had it exploded it would have caused huge devastation or loss of life," Chief Superintendent Alasdair Robinson told journalists.
There was no immediate claim of responsibility for the bomb, but police said a phone call to warn about the bomb used a code word previously used by dissident Republicans.
Politicians have condemned the latest bomb bid, which they said could have caused a massacre on the scale of the 1998 Omagh attack where an 800lb car bomb killed 29 people, including a woman pregnant with twins.
Confirmation that a bomb was discovered in Newry comes after motorists drove through the scene yesterday morning, unaware that a security alert was under way because traffic cones placed by police had been moved.
Acting Chairman of the Northern Ireland Policing Board Brian Rea condemned those responsible.
"This pure purpose of this bomb was to cause death and destruction. The public and political revulsion at the murder of Constable Kerr clearly shows that the people of Northern Ireland do not want any more devastation inflicted on our community and our police service," he said.
"I would urge anyone with information on this van bomb or last week's murder to bring it to the police."
The incident comes as detectives continue to question three men over the murder of constable Ronan Kerr.
A 33-year-old man was detained in the Omagh area yesterday over the booby trap bomb attack that killed the 25-year-old Catholic officer outside his home in the Co Tyrone town last week.
Police were yesterday also given five more days to question a 26-year-old man arrested in Scotland on Wednesday and re-arrested on Thursday, plus a 40-year-old man arrested near Omagh on Thursday.
The under-car bomb that killed Constable Kerr was blamed on dissident republicans who remain violently opposed to the peace process.
It has also emerged that the groups are continuing to target policemen in the wake of his murder.
Senior police sources have said the public outcry following the young officer's death has had no influence on the mindset of extremists, who remain focused on killing members of the security forces.
Detectives have evidence the dissidents have been actively targeting PSNI personnel since the weekend murder.
Officers do not want the nature of the intelligence to be made public for investigative reasons, but they say murder plots are being uncovered at a rate of one a fortnight.
One PSNI source added: "There is absolutely no indication the community outrage has had any impact on the mindset of the dissidents."
No-one has yet claimed responsibility for the murder of Constable Kerr.
But officers have indicated that increasing links and co-operation between disparate organisations means a specific claim is not as relevant to their investigation as it might once have been.
They believe there are nearly as many as 30 distinct groupings operating across Northern Ireland, some claiming to be the Real IRA, some Continuity IRA, some from Oglaigh na hEireann, with other groups claiming no affiliation at all.
Additional reporting: PA