Determined that terrorism will not shatter Northern Ireland's fragile peace accord, Protestants and Catholics united in uncomprehending grief Sunday over the car bomb slaughter of 28 people.

In Belfast, Irish Prime Minister Bertie Ahern and British Prime Minister Tony Blair pledged to do everything within their power to hunt down the bombers and keep the peace process moving forward."The purpose of that bomb was to destroy the work and hope and agreement we built up. Our determination has got to be, these people will never win, and that democracy will triumph over evil," Blair said.

"We will defeat them," declared Ahern at the joint press conference. Ahern vowed earlier to "crush" the IRA dissidents widely blamed for the worst terrorist strike in Northern Ireland's troubled history.

Blair, who cut short a vacation in France to fly to Belfast, pledged to "carry on to my last breath working for peace."

Saturday's blast in Omagh, a religiously mixed town 70 miles west of Belfast, came less than three months after voters in both parts of Ireland overwhelmingly approved plans for a new Northern Ireland government with power shared between its majority Protestants and minority Roman Catholics.

With several residents still missing 24 hours later, soldiers used heat-detecting equipment Sunday to determine whether more bodies lay hidden in collapsed buildings in ravaged Market Street.

The scene on Market Street grotesquely illustrated how 500 pounds of explosives packed into a stolen car can smash so many innocent lives in seconds.

In the rubble were shattered windows, ripped-off roofs, and collapsed walls. Children's diapers were scattered amid fallen glass, bricks and wood planks. A mangled and fire-blackened stroller rested near the carcass of the car bomb. Tatters of school uniforms littered the roadway like autumn leaves. At Old McDonald's side-street cafe, there was half-eaten bread and abandoned coffee.

And on buildings and pavements everywhere, stains of blood remained despite an incessant downpour.

Police said among those killed were 65-year-old grandmother Mary Grimes, her 30-year-old daughter Avril Monaghan who was pregnant with twins, and her 18-month-old granddaughter, Maura. They were on a shopping trip.

Also killed were two Spanish tourists - a 24-year-old woman and 12-year-old boy - and three boys aged 8 to 12 from the Irish Republic. In all, nine children died, along with 13 women and six men.

President Clinton, who is scheduled to visit Northern Ireland Sept. 3, condemned the attack. His spokesman said Clinton has no plans to cancel his visit to Belfast.

"I renew my pledge to stand with the people of Northern Ireland against the perpetrators of violence; they will find no friends here," Clinton said in a statement Saturday. "On behalf of the American people, I condemn this butchery."

Police had unwittingly herded a crowd of people toward the bomb because of a misleading telephone warning.

Of the 220 people wounded in Omagh, about 100 remained in hospitals across Northern Ireland on Sunday, including 11 people in critical condition.

"All of our patients will be disfigured in some way. Some will be

disabled very severely, and some may not survive," said Dr. Laurence Rocke, a surgeon at Belfast's Royal Victoria Hospital, which has treated the victims of many terror attacks.

"You keep thinking you're not going to see it again," he said, his eyes misting over after operating around the clock.

Ulster Unionist Party head David Trimble, the Protestant leader of Northern Ireland's fledgling government, asked church leaders to organize "a national day of mourning," perhaps Tuesday, "for the whole community to come together and express its sorrow, and to show that this evil act will not drive us back into violence."

Gerry Adams, leader of the IRA-allied Sinn Fein party, appealed for people "not to give up hope. People need to have the conviction that we are going to see peace in this country."

But his deputy, Martin McGuinness, rejected a request by former Irish Prime Minister John Bruton for IRA commanders to cooperate with the Irish Republic's police and help catch the dissidents.