Smaller political parties in the North have joined in the condemnation of the bomb attack. The leader of the Alliance Party, Mr Sean Neeson, extended his sympathy to all the bereaved and called on the Irish and British governments to ensure the atrocity was not allowed to derail the peace process.
Mr Neeson welcomed the statement made by the Taoiseach, Mr Ahern, in which he pledged to bring the bombers to justice.
"I would urge the governments on both sides of the Border to do all in their power to ensure that the wish of the people of this island, so clearly expressed in recent months, is not aborted by the people who carried out this brutal act," said Mr Neeson.
The Socialist Party has called for a complete shutdown of Northern Ireland on the first day of the funerals of the victims to demonstrate the outrage felt across the community.
The party's secretary in the North, Mr Peter Hadden, made the call yesterday. He said that any lesser response to the bombing would be inadequate.
"We are calling for the entire workforce, Catholic and Protestant, to stop work to show their outrage. Let us use our power to ensure that this, the worst atrocity of the Troubles, is also the last," he said.
The Workers Party has condemned the bombing and called on loyalist paramilitaries not to be provoked into retaliation.
The party's president, Mr Tom French, said the bombing was "mass murder which nothing can justify".
He called on Sinn Fein leaders to state clearly and unequivocally that their war is over: "Everyone must play a responsible role in denying the terrorists their goal of political instability and sectarian division," said Mr French.
"All parties and the people of Northern Ireland must now unite to show the terrorists responsible that their campaign of slaughter will not stop the peace process going ahead."
Families against Intimidation and Terror (FAIT) has pleaded with loyalist paramilitaries not to retaliate after the Omagh bomb. "I make the strongest possible appeal to the various loyalist paramilitaries not to retaliate. If they do then they will have fallen into the trap laid down by the real IRA," development officer for FAIT, Mr Glyn Roberts, said yesterday. "Please, please, please don't inflict any more violence on this community, more violence will simply make this dreadful situation 10 times worse," he said.
Mr Sam Cushnahan, a spokesman for FAIT, described the Omagh bombing as "a cowardly, callous and barbaric attack carried out by monsters".
Mr Cushnahan applauded the firm pledge given by the Taoiseach to crush the bombers by saying that Mr Ahern provided: "The correct lead when he pledged his government to suppress those involved in the planning and execution of this atrocity."