A pipe bomb has exploded at the Belfast home of the prominent loyalist, Mr Johnny Adair.
The Shankill Road commander is engaged in an internal feud with the UDA leadership.
Some loyalist sources blamed the leadership for the attack. However, others claimed it was carried out by Mr Adair's own supporters as a publicity stunt.
The device exploded early yesterday, just hours after a 37-year-old man was shot in Carrickfergus, Co Antrim.
The victim is critically-ill in hospital. That attack has been widely blamed on the UDA leadership. Adair's close associate, Mr John White, said a small pipe bomb exploded at the back of Mr Adair's home on the Shankill Estate. He said Mr Adair and his family were in the house at the time but slept through the explosion.
The murder attempt in Carrickfergus took place at a house in Dunluskin Gardens. Police said two masked men burst into the house and opened fire, hitting the victim several times. He underwent emergency surgery. One man has been arrested in connection with the shooting.
Det Supt Paul Hamlin, who is leading the investigation, said: "It would appear there was no quarter given." The victim's partner, who was also in the house at the time, was not injured.
The couple's young child, who was playing outside, saw the gunmen run off across the road on to waste ground. Local Ulster Unionist MP Mr Roy Beggs said there was "no justification for this type of barbaric behaviour".
Those responsible should not be allowed "to ride roughshod over the law through fear and intimidation". Sinn Féin MP Mr Pat Doherty said Ulster Unionist leader Mr David Trimble had "an onerous responsibility to tackle and address the violent threat posed by unionist paramilitaries".
The Carrickfergus attack was the third shooting in the North in the past fortnight. On St Stephen's night, Mr Jonathan Stewart (22), was shot dead by Mr Adair's supporters at a house party in north Belfast.
He had no paramilitary links but was a relative of a senior loyalist. Last week, Mr Roy Green (32) was shot dead by the UDA leadership as he left a bar in the upper Ormeau area of south Belfast.
His funeral took place yesterday. A private service conducted by a local Presbyterian minister took place at his parents' home in the loyalist Village area. His coffin was also carried through the neighbourhood.
Police mounted a major security operation in advance of the funeral. Roadblocks were set up in the Donegall Road area and dozens of vehicles were stopped and searched. Several dozen mourners later followed the cortege to Roselawn Cemetery where Mr Green was buried.
A small group of family and friends went to the graveside as four Land Rovers of police officers waited a discreet distance away.
There were no paramilitary trappings at the funeral. Yellow wreaths spelling out "Dad", "Brother", and "Son" adorned the hearse. There had been speculation that Mr Adair and Mr White would attend the funeral.
However, Mr White said that after considering security risks and talking to the Green family, they had decided not to. It is understood the south Belfast UDA commander had warned the men they would be killed if they entered his area.