The North's First and Deputy First Ministers have pledged that the murder of a Catholic man in north Belfast will not derail the peace process. There has been widespread condemnation of the shooting, which was carried out by loyalists.
Mr Brian Service (35), a single man from Ardoyne, was shot at close range several times in the head and back in Alliance Avenue early on Saturday morning. He had been walking home after spending the evening at his brother's house.
Police and ambulance crews were called and the victim was taken to the Mater Hospital where he died soon afterwards.
The RUC said it was investigating motives for the killing, including the possibility that it was a random sectarian attack.
Local people said Mr Service had no political or paramilitary connections and was shot simply because he was a Catholic. The killing was claimed by a previously little-heard-of paramilitary group, the Red Hand Defenders.
In a joint statement, Mr David Trimble and Mr Seamus Mallon said: "We utterly condemn this cynical and dastardly murder and our thoughts are very much with Brian's family.
"If this murder is designed to derail the peace, it will fail. The people of Northern Ireland have overwhelmingly spoken for peace. We are firmly focused on helping to deliver that peace," the statement said.
Mr Service's family appealed for no retaliation. Their parish priest, Father Kenneth Brady, said: "They wish that no one will find any excuse to retaliate because of what happened to Brian. They also wish that the peace talks work so that no one else will suffer this pain."
The victim's cousin, Mr John Service, said: "Brian was just a quiet, harmless man who enjoyed a bit of craic and lived for his family. We don't know why anyone would want to shoot him."
Claiming responsibility for the killing, the Red Hand Defenders said it also opened fire on the Farmers' Inn, on the Colin Glen Road in west Belfast, on Friday night. No one was injured. The North's political development minister, Mr Paul Murphy, condemned the killing and said the British government would not be deflected from making the peace process work.
Sinn Fein has urged nationalists in north Belfast to be vigilant against further loyalist attacks. The party chairman, Mr Mitchel McLaughlin, said: "This is a very dangerous time indeed and we are calling on all the political parties to recognise the potential that an incident like this has to return us to the horrors of the past." Condemning the killing, the Progressive Unionist Party, the UVF's political wing, said it was carried out by "right-wing, fundamentalist, going-nowhere buffoons". However, the Irish Republican Socialist Party, the INLA's political wing, suggested that UVF elements could have been involved and called on the RUC to release the forensic history of the weapon used.
"Speculation that the killers are a splinter loyalist group will not wash with nationalists. History shows that mainstream loyalism has a pattern of using cover-names," a party spokesman said.
Meanwhile, two men are recovering after a "punishment" beating in Antrim. The attack is believed to have been carried out by loyalists.