This article is more than 11 years old

This article is more than 11 years old

Two people, a 17-year-old youth and a 37-year-old man, have been arrested in connection with the shooting of a policeman in Co Armagh last night.

Earlier in the day the dissident Continuity IRA republican group today claimed responsibility for killing 48-year-old Stephen Paul Carroll, from Banbridge, Co Down.

In a coded message, the CIRA said the shooting in Craigavon had been carried out by its North Armagh "battalion".

"As long as there is British involvement in Ireland, these attacks will continue," the message said.

But Martin McGuinness, the Northern Ireland deputy first minister and a Sinn Féin leader, described those responsible for the attack as "traitors to the island of Ireland. They don't deserve the support of anyone".

The peace process "will not fail because there's far too much support for it on this island", he said.

PC Carroll, who was married with a family, was shot dead after he and colleagues answered a woman's call for help, apparently made after a window was broken.

The officers arrived at a housing estate near a Catholic church at Lismore Manor, in the Lismore area of Craigavon, 26 miles south-west of Belfast.

An assassin hiding nearby opened fire from behind the patrol car, fatally injuring the constable – the first member of the Police Service of Northern Ireland (PSNI) to be murdered by terrorists since the police service succeeded the Royal Ulster Constabulary in 2001.

Today, PC Carroll's wife Kate said the killers had destroyed her life as well.

She told the Belfast Telegraph: "A good husband has been taken away from me, and my life has been destroyed. And what for? A piece of land that my husband is only going to get six feet of."

The prime minister, Gordon Brown, insisted the shootings would not signal a return "to the old days".

Speaking in London today, Brown said: "These are murderers who are trying to distort, disrupt and destroy a political process that is working for the people of Northern Ireland."

His message was echoed by politicians on all sides in the UK and Ireland.

The Irish justice minister, Dermot Ahern, said dissidents were unwittingly wrecking their goal of a united Ireland.

McGuinness and the Northern Ireland first minister, Peter Robinson, postponed a visit to the US, where they had been due to meet Barack Obama to celebrate St Patrick's Day.

Sir Hugh Orde, the chief constable of Northern Ireland, appealed for help in catching those responsible for the shooting.

Police say they are looking for a man in a light-coloured top who was seen running from the area. Speaking at a press conference in the early hours of this morning, Orde described the killers as "cowards and criminals" and said: "This has got to stop.

"My police officers are men and women from within this community – your community – who have opted to protect and serve you. They are your neighbours.

"This morning, the Police Service of Northern Ireland has lost an officer," he said.

"But I say to you – the people living on this island – that you have lost a member of your community.

"This was not only an attack on the peace process, it was an attack on the community here."

Orde was urged to call in the SAS in an attempt to thwart the dissident republicans.

But Shaun Woodward, the Northern Ireland secretary, ruled out a return of troops on the streets of the province.

PC Carroll was killed as dissident republicans intensified a terror campaign aimed at destabilising power-sharing in the province.

The CIRA was formed in 1994 as the clandestine armed wing of Republican Sinn Féin (RSF), which split from Sinn Féin in 1986.

"Continuity" refers to the group's belief that it is continuing to fight for the original IRA goal of forcing the British from Northern Ireland.

The latest killing has compounded the sense of shock that followed the weekend's double murder, by the Real IRA, of two British soldiers who died in a hail of gunfire outside the Massereene army barracks in Antrim.

Nationalist politicians joined unionists in condemning the latest murder.

Sinn Féin's local assembly member, John O'Dowd, called on the entire community to back the PSNI investigation and said the killers would not drag Northern Ireland into the past.

Dolores Kelly, the SDLP assembly member for the area, warned: "We are staring into the abyss.

"There is little point appealing to the people who planned and did this, but all of us have to realise we are on the brink of something absolutely awful.

"All of us have to get together to pull ourselves back from the brink."

The party representing one of the main loyalist terror groups, the Ulster Volunteer Force, appealed to the loyalist community to stay calm.

Dawn Purvis, the leader of the UVF-linked Progressive Unionist party, said: "The message remains the same – the perpetrators will not be allowed to damage our peace process."

The two main parties in the Northern Ireland assembly, the Democratic Unionists and Sinn Féin, pledged to work together to ensure that the political process survives.