Death threats have been made against top loyalist politicians and
paramilitaries in Belfast. This follows a feud killing in the city in which a member of the Loyalist Volunteer Force was shot by a rival organisation. The BBC's Northern Ireland security editor Brian Rowan reports.
There is a history of feuding involving the Ulster Volunteer Force and the smaller LVF.
It dates back to 1996 when the UVF stood down the paramilitary leader Billy Wright and his closest associates.
There is a history of feuding between the UVF and LVF
This followed a sectarian murder which had not been sanctioned and, out of this split, the Loyalist Volunteer Force emerged.
In Northern Ireland's paramilitary underworld the two loyalist organisations have not been able to live alongside each other.
There have been many exchanges of gunfire and past killings.
On Tuesday, there was the latest evidence of the tension that still exists between these groups.
In east Belfast, a 34-year-old member of the LVF - Brian Stewart - was shot dead by the UVF.
It has been in the wake of that murder that David Ervine's PUP has been warned that senior members of the party are now being targeted.
That warning - apparently based on intelligence information available to the Special Branch - was passed to the east Belfast MLA by the police on Wednesday.
It read: "Intelligence indicates that a loyalist paramilitary grouping are targeting senior figures within east Belfast UVF-PUP. This is in response to the murder of Brian Stewart."
Brian Stewart was shot dead as he arrived for work
That loyalist paramilitary grouping is undoubtedly the LVF, but some still hope a way can be found to calm what is being described as a "volatile" situation; that something can be done "to end it, not prolong it".
The background to the latest shooting is a mix of threats and warnings.
Senior members of the UVF and the aligned Red Hand Commando were warned of threats to their lives, and there were more general warnings of a possible "hit" in east Belfast and of an attack on a pub elsewhere.
'No military role'
All of these threats were said to come from the rival Loyalist Volunteer Force.
And, later, that organisation was blamed for shooting into two houses and for a pipe bomb attack.
The UVF then struck, targeting and killing Brian Stewart.
He was a member of the LVF, but according to that organisation had no "military" role. This is disputed by other loyalists.
We are in one of those situations in which those who have control of the guns have taken charge
A senior figure in the Loyalist Volunteer Force has also moved to clarify its position on events leading to the murder.
He said those behind the earlier gun attacks and pipe bomb incident had only a "loose association" with the LVF and were acting without sanction.
The paramilitary leader also said the organisation had not issued any threats.
It is not clear if this is the LVF leadership trying to wash its hands of those whose actions sparked this latest feuding and brought about the killing of Brian Stewart.
Certainly the UVF would take some convincing that it was mavericks who were behind the recent attacks and threats.
Indeed, the Ulster Volunteer Force believes it has identified a senior loyalist linked to the LVF and based in east Belfast who it believes has triggered the latest infighting.
Sources talk of "time, energy and influence" being used to try to calm the situation and prevent any "knee-jerk" reactions to the latest killing.
But those same sources know the reality of life in the paramilitary world and know that there are those looking for "revenge".
So far, the loyalist political voices have been silent. We are in one of those situations in which those who have control of the guns have taken charge.