The killing of an Irish police detective during a credit union hold-up has been called an attack on the Irish state and its police force.

According to the Irish Independent, Irish Justice Minister Alan Shatter spoke of his dismay over the shooting. 'I see what occurred effectively as an attack not just on an individual detective but on all members of the force, essentially an attack on the state and this will not be tolerated,' he said.

Shatter was visiting the Dundalk Garda Station in County Louth where the murdered detective Adrian Donohoe had been stationed. Donohoe was shot in the head on Friday night by an armed gang as they stole $5300.00 at a rural credit union.

Shatter also met with detective Joe Ryan, who had been held at gunpoint after witnessing his colleague murdered in cold blood.

'I had the opportunity to meet Joe Ryan who was the other garda detective involved in this event and I expressed my good wishes to him,' the minister said.

'I think we have to admire his courage. He's obviously still upset. I think everyone in the station is understandably upset but I think they're very focused at bringing to justice those who are responsible for the barbaric and callous murder that took place last Friday evening.'

Shatter added that the Irish police force was determined to apprehend the gang. 'I think people are very determined that the individuals that are responsible for this horrendous murder are brought to justice. I think people are stressed but very determined and working very hard,' he said.

Donohoe was a 41-year-old father of two. His wife Caroline was also a police officer and also worked out of Dundalk.

Shatter told the press that the gang must have known police would have been escorting the takings from the Lordship Credit Union in rural County Louth on Friday night. Police reportedly suspect the cross-border criminal gang which stole $83400.00 from the credit union more than a year ago may have been behind Donohoe's murder.

Across the border a burnt out car has been found near a forest in the Darkley area of south Armagh and is being forensically examined by police in Northern Ireland.