The Real IRA, an increasingly violent nationalist group in Northern Ireland, pledged today that it will carry out armed attacks in the United Kingdom as part of its campaign for a united Ireland.

The threat was made by a Real IRA representative in a newspaper interview on Sunday.

The Real IRA, a splinter group of the Irish Republican Army, also claimed responsibility for the 2006 murder of Denis Donaldson, a former Sinn Fein chief administrator and spy for the British, and made threats against Sinn Fein minister Martin McGuiness.

Sinn Fein is the political wing of the IRA;  McGuiness was a senior IRA commander in the 1970s before turning all his efforts to forge a cease-fire.

In the interview with the Sunday Tribune, the Real IRA representative said it planned to attack Britain "when it becomes opportune."

The group - though a small group with only slight support from the people of Northern Ireland - has shown it can make good on a deadly promise.

In 2000 it launched a daring missile attack on the London headquarters of Britain's spy agency MI6. No one was hurt in the assault.

They have also taken responsibility for killing two British soldiers outside a barracks in March.

"Orlaigh na hEireann will continue to strike at the British occupation forces wherever and whenever we decide," the group's representatibe claimed, using the Irish name the group refers to itself as.

The Real IRA broke ranks with the IRA in 1997 when that group participated in the Northern Ireland peace process. In 1998, thirty years of fighting ended between minority Irish Republican Catholics and pro-British protestants.

More than 3,600 people were killed in "The Troubles."

The newspaper said the group will today officially admit to killing Donaldson at a commemoration of the Easter Rising, the 1916 insurrection staged in Ireland against British rule.

Donaldson was shot dead in April 2006, four months after he admitted to being a long-serving British spy, and no group claimed responsibility for his murder.

"The days of a campaign involving military operations every day or every few days, are over. We're looking for high-profile targets, though we'll obviously take advantage when other targets present themselves," he said.

The newspaper said the group will also threaten McGuiness, who denounced last month's attack as well as the killing of a policeman by another splinter group, the Continuity IRA.

"Let us remind our former comrade (McGuiness) of the nature and actions of a traitor," read a printed version of the statement, referring to what happened to Donaldson.

"No traitor will escape justice regardless of time, rank or past actions. The republican movement has a long memory."