Armed Garda checkpoints have been set up across Dublin city in response to recent gangland shootings.
The checkpoints have been established in a bid to halt further feuds erupted, after a man was shot dead at the Regency Hotel and days later, a fifty-five year old man gunned down in the north inner-city.
The second shooting is believed to be a retaliation for the first in an ongoing feud between organised crime gangs based in Dublin and the South of Spain.
The fatal shooting at the Regency, which saw a gang armed with AK-47s open fire at a boxing weigh in, was believed to be a retaliation for the killing of 34-year-old Gary Hutch at an apartment complex on the Costa del Sol last September.
Gary's uncle and brother of notorious Dublin criminal Gerry "The Monk" Hutch, Eddie Hutch, was fatally shot four days after this attack.
The latest killing has led Justice Minister Frances Fitzgerald to call on any other gang members who fear for their lives to come forward and seek protection.
She said: "Tonight's fatal shooting in Dublin is another deplorable example of the ruthlessness of gangland criminals. It seems that some gangs are intent on waging a feud where human life counts for nothing.
"The gardai will take all necessary steps to try to prevent further bloodshed but we have to recognise the challenges they face.
"Members of gangs who have fears for their safety should come forward to the gardai."
