Tight security will be in place this morning as children make their way to Holy Cross primary school and other schools in north Belfast after the murder of a Catholic by the Ulster Defence Association at the weekend.
Police officers are on high alert after Catholic postal workers, teachers and other staff at Catholic schools were identified at the weekend as "legitimate targets" by the Red Hand Defenders, a cover name often used by the UDA. A significant escalation of loyalist violence is feared.
The North's Education Minister, Mr Martin McGuinness, will this morning meet union representatives and others in the school sector to discuss what he called "the unacceptable threat against teachers and school staff".
There will be no postal collections or deliveries in Northern Ireland today and services may not resume until after the murder victim's funeral tomorrow.
Daniel McColgan (20), a father of one, was shot dead as he reported for work at a postal depot in Rathcoole, a sprawling loyalist housing estate on the fringes of north Belfast. The UDA's south-east Antrim brigade leadership is based in the estate. Two people have been arrested and are being questioned.
The killing was claimed initially by the Red Hand Defenders, but the loyalist paramilitary force later claimed the murder in its own name, an unusual move which may signal a new determination by the organisation to step up its campaign of sectarian attacks.
Mr Alan McQuillan, Assistant Chief Constable of the PSNI, confirmed to The Irish Times yesterday that security was being stepped up to counter the threats, but he would not give details of any measures taken or planned. He believes some INLA members were involved in last week's north Belfast riots and he also linked an arms and explosives find in the city yesterday to that organisation.
"Last week, during the disturbances in the nationalist area of Ardoyne, we had a number of pipe-bombs thrown at us," he told the BBC. "We believe that those attacks and the arms find last night are clearly the responsibility of the INLA."
The Police Service is coming under increasing pressure to obtain results in its drive to counter loyalist violence. The Taoiseach, Mr Ahern, noted yesterday that there had been "few or no arrests" following an upsurge in UDA violence last year which had led to the Secretary of State, Dr John Reid, stating that his government viewed its cessation as a fraud.
The UDA, along with other loyalist paramilitaries, called a ceasefire in October 1994. Since then, the Combined Loyalist Military Command structure has disintegrated and feuding among various groups has broken out.
Mr Ahern called on the Police Service and Dr Reid to do what they could to get results. "It would be surprising if some of the leaders of the loyalist gangs are not known. And, of course, people have felt that something was going to happen because tension had built up over the past few days. They feel that more could be done in the policing area," he said.
Last night, the First and Deputy First Ministers, Mr David Trimble and Mr Mark Durkan, called for the immediate lifting of the threats against Catholic teachers and postal workers. They also insisted that all attacks against public-sector workers such as ambulance staff, fire-fighters and bus and train drivers had to stop.
"Workers should be able to earn a living free from any form of attack or intimidation. Schools should be a haven for children, a place where they can learn and understand more about the importance of tolerance and respect for others. Attacks on pupils travelling to and from school, which have been witnessed from both loyalist and republican communities, should also cease immediately," they added.
The Sinn Féin president, Mr Gerry Adams, said yesterday that the UDA's "game plan" was to undermine the peace process and draw republican organisations into conflict.