The Taoiseach, Mr Ahern, led condemnation in the Republic of the killing of the three Quinn children by describing "these savage, callous and sectarian murders" as an attack on the vast majority of people in the North who had pledged themselves to peace and the democratic process.
After offering his heartfelt sympathy to the Quinn family and "all families who have suffered any form of intimidation in recent days", Mr Ahern appealed for calm among nationalists and for restraint on all sides. "Despite the pressures and fear the nationalist community are experiencing at present, I would ask them to remain calm and any protests during the current marching season should be carried out with dignity and restraint."
The Taoiseach said he believed this "horrific act" was a consequence of heightened tension which built up over the past week. He renewed his call for dialogue and, in relation to Drumcree, for the processes of using intermediaries and mediation to be pursued. He acknowledged "the right to march, the right to parade. But there has to be dialogue."
The Minister for Foreign Affairs, Mr Andrews, expressed sorrow and outrage at the murders. "The absolute horror of this evil act ought to bring people in Northern Ireland to their senses. It is time for all who want to see tolerance replace hatred to demand an immediate end to bitterness and conflict."
He hoped, as a clear rejection of "the mentality behind this outrage", those involved in the crisis at Drumcree would redouble their efforts to agree a peaceful accommodation.
His call was echoed by other politicians, church leaders and the STOP '96 - solidarity to organise peace - campaign, which called for the opening of books of condolences in workplaces and public offices throughout the island.
The Ballymoney murders were part of "an organised descent into territorial savagery derived directly from the ritualised confrontation at Portadown", according to the Fine Gael leader, Mr John Bruton.
This sort of community level confrontation was even more dangerous than organised terrorism. "It will tear aside the veneer of civilisation that has been painstakingly created over centuries and leave wounds that will never heal," Mr Bruton said.
Church leaders on both sides should comprehensively withdraw support for those involved in that confrontation until a compromise was reached, he said.
The Church of Ireland Archbishop of Dublin and Glendalough, Dr Walton Empey, said he and many others were "conscious of the black cloud of violence and sectarianism that has spread and continues to spread over Northern Ireland".
The image of Christianity in Ireland flashed over all the world was one of betrayal of the teaching and the mind of Christ. "For members of the Church of Ireland in the Republic in particular, the daily pictures of Drumcree church and the violent activities taking place in the surroundings are a source of shame, of anger, of great pain and embarrassment."
Speaking at the annual ecumenical service to mark "Sea Sunday" in Kinsale, Co Cork, Archbishop Empey said he shared "that shame, that anger and that feeling of utter helplessness in the face of Orange and Green intransigence".
The Labour Party leader, Mr Ruairi Quinn, said on RTE Radio 1's This Week that he hoped "this horrendous event" would lead to a change of heart by both Orangemen at Drumcree and Garvaghy Road residents and create a space for the process of politics and compromise that was evident in the wake of the Good Friday Agreement to come to the fore again.
Three young children had become "the entirely innocent victims of the sectarian standoff that had been allowed develop over the past week", said the Democratic Left leader, Mr Proinsias De Rossa. "If we have learned anything from events in Northern Ireland over the past 30 years, it is that confrontations of this nature invariably escalate into death and destruction."
