Updated

A fringe political party linked to Irish Republican Army dissidents on Thursday predicted more bloodshed over Northern Ireland, describing it as a territory under British occupation.

Richard Walsh, publicity director for Republican Sinn Fein, told a Belfast news conference that traditional Irish republicans would never accept the 1998 peace accord that forged a joint Catholic-Protestant government in Northern Ireland — but kept the territory within the United Kingdom.

Republican Sinn Fein is the rarely seen public face of a splinter group called the Continuity IRA, which claimed responsibility for fatally shooting a policeman through the head March 9.

It was the first paramilitary killing of a policeman since 1998, and came two days after another breakaway group, the Real IRA, killed two off-duty, unarmed British soldiers outside an army base. Both dissident groups are trying to unravel the IRA's 1997 cease-fire and the power-sharing deal it inspired.

The IRA killed nearly 1,800 people during its failed 1970-97 campaign to force Northern Ireland into the Irish Republic. In 2005 it formally renounced violence and disarmed, and two years later the IRA-linked Sinn Fein party recognized the authority of the Northern Ireland police as part of its power-sharing deal with Protestants.

Walsh said Sinn Fein had betrayed traditional IRA values and was "administering British rule in Ireland ... and supporting the armed forces of occupation in our country."

"The reality is that when you have occupation within a country there is invariably resistance, including armed resistance," Walsh said. "And we have always upheld the right of the Irish people to use any level of controlled and disciplined force to drive the British out of Ireland. We make no apology for that. ... It's regrettable that loss of life occurs, but sadly it's an inevitable fact."

When a reporter asked Walsh whether he could justify the murder of police officers who enjoy support from both the British Protestant and Irish Catholic sides of the community, he rejected the premise.

"I don't accept the use of the term 'murder.' They're acts of war," he said.

Walsh spoke alongside several young men whom police targeted in house raids in the working-class Catholic neighborhood near the scene of the March 9 killing. One of those present was arrested March 14 on suspicion of involvement in the killing, but was freed Wednesday without charge. They wore caps or hats to conceal their faces from television cameras and photographers.

In a related development, a third person charged in connection with the policeman's killing was arraigned Thursday in a court southwest of Belfast.

Two people — a 17-year-old boy and a 37-year-old former Sinn Fein councilman — were charged earlier this week with murdering the policeman, 48-year-old Constable Stephen Carroll, an English-born Catholic.

The latest suspect, a 21-year-old man, was charged with concealing information about the killing. Police and court officials ordered news organizations not to reveal any details about the man because it could put his life in danger.

The man didn't speak during the hearing, and his lawyer didn't apply for bail. He was jailed pending his next court appearance April 17.