A bitter split in the IRA's ranks led to the murder of a man in south Armagh, PSNI Chief Constable Hugh Orde claimed today.
Further bloodshed could follow the shooting of Keith Rogers in a village close to the Border last week, he warned.
Mr Orde confirmed his detectives were prepared for revenge strikes as the violent feud in the republican border area intensified.
He said: "It clearly was a fall-out between two factions of the Provisional IRA. That sends a very worrying message to us."
Mr Rogers (24), an IRA volunteer from Co Louth, was gunned down during a shoot-out at a petrol station in the village of Cullaville.
Up to 10 men were involved the fight last week, which left two other men wounded, including Mr Kevin O'Callaghan (40).
Mr Orde said his officers were braced for more shootings. "We are looking at that as a contingency," he said. "In any situations like that you have to look at the potential fall-out. There may be consequences as a result of the attack."
Relatives of Mr O'Callaghan - who denied shooting Mr Rogers - claimed the murder victim was part of a masked and armed gang that tried to kidnap his son Kevin during the confrontation.
Bitter rivalries had flared over a land dispute involving his family, they added. Hostilities were stepped up last month when Mr O'Callaghan's brother, Danny, lost a foot in a horrific paramilitary-style punishment attack.
At Mr Rogers' funeral, mourners were told he had been murdered by degenerate law-breakers masquerading as republicans.
PA