The garda shot dead in Co Louth last night has been named by gardaí as Detective Garda Adrian Donohoe who was attached to the Detective Unit in Dundalk.
The fatal shooting happened at around 9.30pm at the Lordship Credit Union in Bellurgan, Jenkinstown near Dundalk.
Garda Commissioner Martin Callinan said he was deeply saddened to hear of the death of his colleague.
He said: "Detective Garda Donohoe died as a result of injuries sustained in the course of his duty following a shooting incident in Dundalk last night.
"At this time my thoughts and prayers and those of the entire force are with the family, friends and close colleagues of Adrian."
Minister for Justice Alan Shatter said gardaí "will spare no effort in ensuring that those responsible are brought to justice. In doing so, they have the unswerving support of the Government and Irish people at this very difficult time".
Detective Garda Donohoe was one of two detectives on escort duty when the shooting occurred.
It is believed four armed men were waiting outside to rob the credit union and moved to hold up staff at gunpoint as they were leaving work.
Detective Garda Donohoe approached the raiders and was shot.
His colleague has been severely traumatised but is otherwise unhurt.
The raiders fled the scene in what is believed to have been a dark-coloured car.
Gardaí are still trying to establish the circumstances surrounding the shooting and are appealing for anyone with information on the incident to contact them at Dundalk Garda Station on 042-9388400 or via the Garda Confidential Line on 1800 666 111.
The area has been sealed off and the PSNI has also been informed.