Prayers will be said at masses across the Irish Republic for murdered police officer Adrian Donohoe.
Catholic Primate Cardinal Sean Brady said he had been deeply saddened by the shooting, which has not only sparked revulsion among the tight-knit police fraternity and with political leaders but has also plunged the wider society into a deep sense of dismay.
Cardinal Brady said: "It has shocked and horrified the entire community. The taking of innocent life is always wrong. Detective Garda Donohoe lost his life as he carried out his duty in the service of society. I appeal to all of society to unite in rejecting such wanton violence and criminal lack of respect for human life."
Detective Garda Donohoe, a 41-year-old father-of-two, lived and socialised in the area where was killed while on duty on Friday night. Originally from Co Cavan, he came from a dedicated policing family - his widow Caroline and two brothers also serve in the force. He leaves behind a son and daughter.
Local sources said they believed a criminal gang and not dissident republicans were responsible for the murder, but police have said it is too soon to know.
Friends and former colleagues described Mr Donohoe as a popular community figure, diligent policeman and devoted family man. He was part of a specialist cash escort unit tasked to the Lordship Credit Union at Bellurgan, Jenkinstown close to the border with Northern Ireland.
The rural premises were closing when the armed gang struck just after 9.30pm. Det Garda Donohoe was shot without warning as he jumped out of his patrol car. He did not have time to draw his own police issue weapon.
Gardai said four men were involved in the botched robbery and escaped in a dark coloured vehicle. It is not known whether they fled across the border into Northern Ireland or headed south.
He is the first police officer to be killed in the Irish Republic for 17 years. Detective Garda Jerry McCabe was gunned down in similar circumstances outside a post office in Co Limerick in 1996.
Irish President Michael D Higgins and Taoiseach Enda Kenny led the tributes. Garda Commissioner Martin Callinan vowed to do everything in his power to catch the killers. He said: "Resources will not be an issue. We will put all our energy towards finding out precisely who was behind this robbery."