ASSOCIATED PRESS WRITER

SHAWN POGATCHNIK

BELFAST, Northern Ireland (AP)—A deadly IRA bombing and the bitterness it has reinforced in Protestant areas have undermined the political efforts of Northern Ireland’s two most prominent Catholic politicians.

‘‘We are appalled. Our feelings in this community run high. We are indignant, bitter and even vengeful,’‘ the Rev. Brian Moore, a Presbyterian minister, told 6,000 people gathered Monday at the site where 10 people died in Saturday’s bombing.

‘‘But it is God’s prerogative to judge. Remember, our lives and the lives of our children cannot be built on violence and more violence,’‘ he appealed, as fears of retaliation by Protestant extremists grew.

He stood a few yards from where the Irish Republican Army bomb destroyed a fish shop and the offices of the Ulster Defense Association, an outlawed Protestant-based group committed to killing both IRA supporters and Catholics uninvolved in the province’s political troubles.

The UDA said it would exact ‘‘terrible revenge’‘ on Catholic nationalists for the bombing in the Shankill district.

Two Catholics died Monday after being shot by loyalists. Martin Moran, 22, was shot late Saturday but died Monday. A second man, who was not identified, was killed Monday in north Belfast, and the pro-British extremist Ulster Volunteer Force claimed responsibility.

In Washington, the State Department condemned the bombing ‘‘in the strongest possible terms.’‘ Acting spokeswoman Christine Shelly called on perpetrators from both sides to end their acts of violence.

Britain’s Prime Minister John Major spurned an overture by Gerry Adams, head of the IRA-supporting Sinn Fein party, to salvage the fruits of his peace talks with moderate Catholic leader John Hume.

Adams said he would tell the outlawed IRA to stop its killing if the British government reacted ‘‘positively’‘ to secret proposals agreed to by Adams and Hume, the respected leader of the moderate Social Democratic and Labor Party.

The two leaders handed a confidential report to the Irish government last month on the expectation that Dublin officials would discuss the Hume-Adams ideas with their London counterparts.

But a meeting between the Irish and British governments planned for Wednesday in Belfast was canceled because of the Shankill bomb.

Major, in Cyprus for a Commonwealth summit, called Adams’ proposal ‘‘tantamount to blackmail.’‘ The prime minister said the IRA would have to call off its campaign against British rule before his government would consider talking with Sinn Fein.

Sir Patrick Mayhew, Britain’s secretary of state for Northern Ireland, told Parliament in London that the government would not negotiate with murderers. ‘‘In this democracy, no politicial purpose … will be advanced a single inch by the threat or the use of violence,’‘ he said.

Politicians in the province’s two main pro-British parties warned that any concessions now would provoke ‘‘massive reaction’‘ from pro-British ‘‘loyalists,’‘ who this year have killed as many people as the IRA.

‘‘Negotiating with Sinn Fein is the road to disaster in Northern Ireland,’‘ said John Taylor of the Ulster Unionists. ‘‘… If you start giving credibility to the IRA and their political spokesmen, you will find there will be a massive reaction on the loyalist side of the divide.’‘

‘‘The Hume-Adams deal is not a peace process,’‘ agreed Peter Robinson, deputy leader of the Democratic Unionists. He called their secret proposals ‘‘basically an attempt to put a nationalist agenda forward and to agree nationalist tactics.’‘

Nearly 3,100 people have been slain in 24 years of civil conflict in Northern Ireland.