BELFAST -- Vengeful Protestant gunmen killed six Catholics enjoying Ireland's night of World Cup glory in a country pub and raised fears of a fresh spiral of Northern Ireland's tit-for-tat sectarian bloodshed. The outlawed Ulster Volunteer Force claimed responsibility for the attack Saturday night on a Loughinisland pub, 50 kilometers southeast of Belfast, where Protestants and Catholics were watching live coverage of Ireland's 1-0 win over Italy in its opening World Cup game in New York. Two gunmen burst into the small public bar and sprayed it with automatic gunfire, killing five people instantly. One man died later of his wounds, one was still seriously ill on Sunday and four more were wounded in the attack. Irish Prime Minister Albert Reynolds said in New York, where he was at the game, that the attack was incomprehensible. It was "barbaric savagery," said Reynolds, whose government agenda is topped by plans to end the province's 25-year conflict. The attack struck at the heart of Anglo-Irish attempts to forge a new relationship between the British-ruled province and the Irish Republic to the South. Gerry Adams, leader of Sinn Fein, the political wing of the Irish Republican Army which is fighting to end British rule in Northern Ireland, said Monday that the IRA would not retaliate."Retaliation attacks on ordinary Protestants can play no part in Republican strategy," Adams told BBC radio.