Irish police have launched a hunt for the gang responsible for killing a detective during an attempted armed robbery near Dundalk.
The Garda detective, who has been named as Adrian Donohoe, was shot dead in a botched hold-up of a credit union near the border with Northern Ireland around 9.30pm on Friday.
Garda sources said that after shooting the police officer the raiders seized the stolen money and drove off. Four men, who are believed to have fled the scene in a grey Volkswagen Passat, are being sought by the force.
Armed patrols were deployed throughout the region overnight and the Police Service of Northern Ireland has been asked for assistance in case the gang fled over the border.
The Irish president, Michael D Higgins, has described the killing as "a dreadful crime" that the whole country would be "truly appalled by".
The Sinn Féin president and County Louth representative, Gerry Adams, said he was deeply shocked by the detective's murder. "I extend my deepest sympathies to his family and colleagues, and appeal to those with information about this crime to co-operate with the Gardai," he said.
Jim Loughran, a Sinn Féin councillor in the part of County Louth where the shooting took place, described Donohoe as a quiet family man. "I just spoke to him last week on the street in town. I can't believe this has happened," he said. "This was not just an attack on a Garda detective, it was an attack on the whole community."
Donohoe is understood to have been married with three children. He lived just over half a mile from the scene of the attack.
The Irish justice minister, Alan Shatter. said: "The Irish people … will share my revulsion and horror that a garda has so tragically lost his life in the course of his duties."
The Lordship Credit Union, where the killing took place, was described as a hub of the small community. It is believed staff were locking up when the incident occurred.
Councillor Declan Breathnach said it was not unusual for it to remain open late. "It would be fairly busy on a Friday evening, with some people just getting their week's pay or wanting to sort out money for the weekend," Breathnach said. "This was just such a despicable, heinous act. I still can't believe it but I utterly condemn it."
Fianna Fail justice spokesman, Niall Collins, pledged his party's full support to Garda commissioner, Martin Callinan.
Gardai have appealed for witnesses to contact them at Dundalk garda station.
Official statistics have shown that crime, apart from burglary, has been falling since the republic's economic downturn started in 2007-08, although gun crime among gangs, particularly in Dublin, has continued to make headlines.
The death of the Garda officer comes 17 years after a detective was shot by members of the Provisional IRA while he was taking part in an escort for a cash delivery to a post office in County Limerick.
John Parker, president of the Garda Representative Association, said: "This dreadful news is what every police family fears. At this time the wider garda family will be doing everything possible to support the late garda's relatives and loved ones, friends and colleagues."