The status of the paramilitary ceasefires is under review after a fourth consecutive night of sectarian violence in east Belfast, according to the North's Security Minister, Ms Jane Kennedy.
Four people, among them a police officer, were shot and a bus- driver was injured by flying glass after his vehicle came under gunfire during the disturbances in the lower Newtownards Road area on Monday night.
Ms Kennedy said both loyalist and republican ceasefires were being closely and continuously monitored.
"Although the assessment of the ceasefire remains unchanged, this is a worrying development. The use of handguns or weapons of any sort in these situations is a very dangerous development," she said.
While insisting the status of the ceasefires was a matter for the Northern Secretary, Dr John Reid, the PSNI Assistant Chief Constable for Belfast, Mr Alan McQuillan, said he had no doubt that mainstream loyalist and republican paramilitaries had been orchestrating the disturbances.
"On the loyalist side, we see clear evidence that the UDA and the UVF have been involved in this. Certainly in terms of the street disorder on the republican side we have seen large numbers of members of the IRA, many of them from outside the area, in the area. We believe that they are involved in organising the violence."
The rest of Belfast would be paying the price for the disturbances in east Belfast in terms of a reduced police service, Mr McQuillan added.
Condemning the civil unrest, the SDLP leader and Deputy First Minister, Mr Mark Durkan, said there should not be any forms of "permissible violence" or accepted locations for it in society.
"People of all backgrounds and persuasions have the right to live in peace and safety in their own homes and streets. It seems clear that different paramilitary elements are prepared to foment tension and trouble in the hope that they will profit from the fallout," he said.
A DUP MLA for the area, Mr Sammy Wilson, blamed "well-known republicans" from north Belfast for orchestrating the violence, claiming their objective was to drive people out of Protestant areas and take them over.
The Sinn Féin president, Mr Gerry Adams, said senior republicans had gone into the area to calm the situation.
"I want to use any influence I have to say very clearly that this has to stop. I do not wish to speculate on how it started - all I am saying is that it has to cease. It is a miracle that nobody has been killed so far. The people of east Belfast, unionist and republican, deserve better."
Mr Adams said he had spoken to the Northern Secretary about the situation and was hoping to hold talks with the Taoiseach and with the Progressive Unionist leader, Mr David Ervine, whose party politically represents the UVF.
Mr Ervine, who also held talks with Dr Reid, insisted earlier that the nationalist Short Strand enclave had been turned into a "no-go area" for the security forces and that members of the Provisional IRA were orchestrating the disturbances.
An Alliance Party councillor, Mr David Alderdice, said he had witnessed the same feelings of fear and despair while visiting people on both sides.
The Church of Ireland Bishop of Down and Dromore, Dr Harold Miller, said the situation was "absolutely unacceptable".
"I ask politicians and community leaders to join with me and with other church leaders to say that the people of east Belfast want peace and to demand that those perpetrating the violence stop immediately before someone is killed," he said.