Two men were last night being questioned by detectives about Saturday night's murder in Belfast of two UDA members, including the organisation's south-east Antrim commander, John Gregg.
The dead men appear to have been victims of the ongoing loyalist feud between the mainstream UDA movement and the Shankill Road "C" company of the UDA which supports Johnny Adair.
In a statement last night, the Shankill UDA, using the cover-name of the Red Hand Defenders, admitted the double murder.
As members loyal to the UDA leadership threatened retaliation against Johnny Adair's supporters, who have been blamed for the killings, there were calls for the reintroduction of internment.Former Ulster Unionist MP, Lord Maginnis of Drumglass, said that although some people might oppose such a move, it was necessary to prevent "Mafia gun law".
John 'Grug' Gregg (45) was shot dead in a gun attack near Belfast docks on Saturday night. He had been returning from a Glasgow Rangers match in Scotland.Another UDA member, Robert Carson (33), was also killed.
A senior UDA member said last night that the organisation had been on the brink of resolving the feud, but the Shankill grouping had pulled out of a deal just hours before the murders.
"There is absolutely no chance this feud will be settled peacefully now," he said."The people who murdered John Gregg have made sure of that."
The North's Security Minister, Ms Jane Kennedy, said: "The people of Northern Ireland are sick of bracing themselves for yet another spat of brutal killings and shootings amongst criminals. The security forces will continue to do everything to put those involved behind bars where they belong."
Ulster Unionist Assembly member, Sir Reg Empey, called on the mainstream UDA not to retaliate.
Mr Gregg was one of the five inner council members who voted to expel Adair from the organisation last autumn.
Adair was returned to prison last month by the Northern Secretary, Mr Paul Murphy, who claimed he had broken the terms of his early release under the Belfast Agreement. Senior security figures believed the move would neutralise Adair's Shankill Road 'C' company and end the feud.
More than 30 loyalists, including Adair supporters, were on the Stena HSS which docked in Belfast from Stranraer at 10 p.m. on Saturday. It is believed someone on board tipped off 'C' company about Gregg and Carson's presence.
The two men got into a taxi. Another car pulled up beside it as it stopped at traffic lights at the junction of Nelson Street and Great Georges Street at 10.15 p.m. Several shots were fired, killing the UDA members. The taxi-driver was also shot and is in a critical condition.
Two other men who were in the taxi, including Mr Gregg's 18-year-old son Stuart, were injured. Mr Gregg, a married man, also had two step-daughters.
Meanwhile the homes of three loyalists were targeted in separate attacks linked to the feud. A shot was fired through the window of a house in Carmeen Drive, Rathcoole, Co Antrim. The owner, Mr Samuel Duddy of the UPRG, was not at home and no one was injured. Adair's supporters have been blamed. They were also responsible for attacking a house at Albert Road in Carrickfergus, Co Antrim, with a pipe bomb. It is understood the North Belfast commander of the UDA, nicknamed "the Egyptian", had been staying there. The device failed to explode.
A man narrowly escaped injury after shots were fired at a house in Kilmory Gardens in the Tullycarnet area of east Belfast. The mainstream UDA was responsible.