Figures associated with the Ulster Defence Association are believed to have been responsible for three killings in Belfast. Two of these have been claimed in the name of the Loyalist Volunteer Force, the group set up by the murdered loyalist, Billy Wright.
UDA elements are also believed to have shot dead the Catholic taxi driver, Mr Larry Brennan, on Monday evening, loyalist sources say.
Two other murders in Belfast - Mr Eddie Treanor (31), shot dead on new year's eve, and Mr Terry Enright (28), shot dead on January 11th - were also carried out by UDA-associated figures.
Mr Treanor was killed when a gunman opened fire on the patrons of a Catholic pub on Cliftonville Road. The gunmen drove up Rosapenna Street and along the Oldpark Road towards the Shankill. The UDA has used this escape route so often in its sectarian killings of Catholics that it is known to west Belfast loyalists as the "death run".
Mr Enright, the doorman shot outside a city centre club 11 days ago, may have been killed in mistake for another man, but the same UDA elements are also suspected of being responsible. These people, it is thought, were intent on killing another man in the club who may have double-crossed other UDA figures in a drugs deal.
In both cases, the murders were claimed by anonymous telephone callers to news organisations using a codeword associated with the LVF. A senior loyalist source in Belfast said of the killings: "The only thing the LVF supplied was the codeword."
The RUC has not stated publicly who it believes is responsible or if weapons used were associated with previous loyalist attacks. In the case of Mr Treanor's murder the Uzi submachine gun could be a new weapon with no ballistic records.
According to security sources in the North, the UDA received a shipment of these weapons around 1995. The sources suggest there might be "hundreds" of such weapons in the loyalist hands.
One UDA figure suspected of being behind recent attacks is a man in his twenties from the Shankill Road. It is believed he was behind the murder of a Catholic man, Mr John Slane, who was shot dead in front of his eight children at his home in west Belfast on March 15th last year.
It is also suspected the UDA man planted booby-trap bombs under cars belonging to a number of republicans, badly injuring one leading republican in north Belfast last January.
Loyalists say the UDA man also shot dead Robert "Basher" Bates, the loyalist assassin who served a life sentence for murdering several Catholics in Belfast during the 1970s. He shot Bates last June 11th out of a sense of personal grievance dating from his childhood about the murder of a near relative.
Bates had a long association with rival loyalist group, the UVF, whose members began searching for the young UDA man in order to kill him. The UDA man went on the run from the Shankill and may have moved out of Belfast. He began associating with other loyalists linked to the LVF. But it is said he maintained close links with several of his UDA associates in the Shankill and threatened leading UDA and UVF members in west Belfast.
Recently, the UDA man has been seen frequenting a loyalist club in south Belfast, not far from Dunmurry where the UDA man, Mr Jim Guiney, was shot dead on Monday morning by the splinter republican group, the Irish National Liberation Army. It is also near the spot where taxi driver Mr Brennan was assassinated on the Ormeau Road. This murder was almost certainly sectarian, carried out in retaliation for the murder of Mr Guiney.
The three other loyalist assassinations since December 11th were the work of unknown loyalists connected to the LVF. These victims were Mr Gerry Devlin, shot dead outside a GAA club in north Belfast; Mr Seamus Dillon shot dead a day after the murder of Billy Wright; and Mr Fergal McCusker, shot dead in Co Derry at the weekend.
There are now concerns among loyalist paramilitaries that young dissidents in their ranks might rally behind rogue UDA and LVF elements if the current round of violence continues and there are further assassinations of loyalists.
According to loyalist sources there is particular concern that the UDA might have insufficient control of its younger members to prevent them from embarking on a serious campaign of sectarian violence. Since the loyalist ceasefire was called in October 1994 the UDA embarked on a recruitment campaign joined by hundreds of young men, many in their teens. A lot of these young men were involved in rioting and sectarian confrontations last summer.
The UDA leadership is almost permanently riven by disputes. Some of its leading members are suspected of being involved in the drugs trade and this is a major source of ill-feeling among other loyalists. The principle concern is that young UDA militants will break away completely, taking the UDA arms with them to form an alliance with the LVF. Until now, the LVF has had no presence in Belfast, where the established loyalists jealously guard their territory.
Members of the other loyalist organisation, the UVF, are watching the UDA with growing alarm. It, too, is understood to be encountering growing militancy among its younger members and is reported to be angry with the Government's unilateral decision to release IRA prisoners from Portlaoise. The UVF may still be considering ending its ceasefire, loyalist sources say.
It is not clear how the current violence and the involvement of UDA figures will affect the talks process.
All three of the North's main paramilitary organisations have transgressed the Mitchell Principles of June 1996, which set conditions for entry into the Stormont political process.
The principles, drawn up by the talks chairman, Senator George Mitchell, stated that all parties had to affirm their total and absolute commitment to democratic and exclusively peaceful means of resolving political issues and to renounce and oppose any effort by others to use force.
The principles also demanded an end to punishment shootings and killings. All three main paramilitary organisations, the IRA, UVF and UDA, have blatantly defied this principle. Despite a rise in the number of such incidents, both governments have ignored the knee-cappings and other punishments meted out by all three groups.
There was no suggestion that Sinn Fein should withdraw from the talks two weeks ago after the attempted murder of a man in a shooting in a Belfast public house by the IRA using its cover-name of Direct Action Against Drugs. Transgressions of this kind were common during the first IRA ceasefire when it shot dead eight men who it alleged were drug dealers. The governments ignored these killings also.
But during its ceasefires, the IRA has refrained from attacking members of the security forces or of causing damage to property with bomb attacks.
During the 18 months up to last July, when the IRA resumed its campaign, the main loyalist paramilitaries carried out attacks but did not issue admissions of responsibility.
The UVF planted a bomb at the Sinn Fein office in Monaghan town last February. The device contained 15kg of commercial explosives but did not explode.
The loyalist parties remained in the talks process despite a widespread understanding that their military elements were active. Nationalists accused the governments of granting the loyalists a "no claim, no blame" allowance by not expelling them from the talks.
The Ulster Democratic Party, political wing of the UDA, is now in the precarious situation of representing paramilitaries who are seen in the North as having fully resumed their campaign of violence.