Gardaí believe a retaliatory attack may be planned after a suspected gangland killing in Tallaght this morning.
Gardaí say the man was hit by a number of shots outside a house in Belgard Heights at 9.10 a.m. He was dead on arrival at Tallaght General Hospital.
Garda sources said the man was known to them and had close links to a major Dublin heroin dealing gang.
It is believed the man’s killer was waiting in a van outside the house. As he saw his target, he approached and opened fire before escaping with another man on a motorbike.
A garda spokesman said: "We believe there were two people involved although we have no descriptions of them at the moment.
"We are appealing for anybody who saw a large motorcycle or a white Nissan vanette in the Belgard Heights area around 8.45 and 9.10 a.m. this morning to contact any Garda station," he added.
A garda source said the dead man had worked as a drugs courier for one of Dublin’s biggest heroin gangs.
He was arrested last November by the Drugs Unit in a special anti-drugs operation.
During a raid on his home they discovered IR£100,000 of heroin in the garden.
Police were today following a line of inquiry that he may have been killed on the orders of one of the gang's leaders.
With strong suggestions that the killing was gang-related, they feared a retaliation killing could follow.