Britain said on Wednesday it no longer considered two Protestant paramilitary groups to be observing ceasefires, after heavy rioting in Northern Ireland's capital at the weekend.
The action is largely symbolic but officials said it was a clear signal to extremists that violence in the province, slowly emerging from three decades of violence in which 3,600 people were killed, would not be tolerated.
Mobs hurled petrol bombs, set fire to hijacked cars and shot at police in what locals described as the worst rioting in the province for years.
Tension has mounted since the government started to scale back its security presence following a commitment in July by IRA paramilitaries to disarm.
Infighting between Protestant groups has also led to deadly violence.
Secretary of State Peter Hain said ceasefires declared by the Ulster Volunteer Force and The Red Hand Commando had collapsed.
"The actions of the UVF in respect of the ongoing feud, taken together with the very serious attacks against the security forces over the course of 10 and 11 September amounted to a breakdown in their cease-fire," Hain said in a statement, reports Reuters.
According to Times, the Ulster Defence Association in North Belfast said: “We are instructing our own membership to avoid any confrontation on the streets and steer away from any acts of violence.”
The Provisional IRA, which carried out the Northern Bank raid last December and murdered Robert McCartney, has never been specified, although the Government did suspend some of its Westminster funding.
At least 60 police officers have been injured in the recent rioting in Belfast and surrounding towns. Police hunting the gunmen and bombers who attacked police and troops when a rerouted Orange Order parade descended into chaos on Saturday, have made 63 arrests so far. One man was in court yesterday accused of possessing seven guns, home-made explosive and terrorist clothing.
The disorder has caused millions of pounds of damage. Business and tourist experts fear that the street disorder could inflict severe damage to investment hopes.