PSNI detectives investigating the murder of Constable Stephen Carroll in Co Armagh have arrested two men.

The men, aged 17 and 37, were arrested in the Craigavon area of Co Armagh.

The older man was detained at around 5pm.

Both men are being questioned by PSNI detectives in the Serious Crime Suite at Antrim police station.

The arrests follow a day of police activity in the area around the scene of the killing.

Earlier, the Continuity IRA claimed responsibility for the murder.

In a coded message, the dissident republican group said the shooting in Craigavon was carried out by its north Armagh battalion.

It said: ‘As long as there is British involvement in Ireland, these attacks will continue.’

There has been widespread condemnation of the killing.

At around 9.45pm last night, police responded to a request for assistance from a member of the public at Lismore Manor in the town.

Two police vehicles arrived in the area. As officers got out of one of the vehicles, gunshots were fired at them.

48-year-old Constable Carroll (right) was struck by gunfire and subsequently died from his wounds.

The victim, who was married with children and lived in the Banbridge area of Co Down, had more than 20 years’ experience and was well known in the area.

He is the first policeman to be murdered in Northern Ireland since 1997 and his death comes two days after the Real IRA killed two British soldiers in Antrim.

Taoiseach Brian Cowen spoke by telephone to British Prime Minister Gordon Brown this evening.

Aftewards a Government spokesman said both leaders re-affirmed their joint commitment to facing down the threat posed by those behind the latest acts.

Mr Cowen said it was with deep sadness and disgust that he learned of what he called the despicable murder of a policeman as he was doing his duty in serving the community.

Mr Cowen said Constable Carroll was serving all the people of Ireland and protecting the peace people now treasure.

He said the PSNI has the full support of all the Irish people in tracking down those responsible, whom he called evil people.

Mr Cowen confirmed the Justice and Foreign Affairs ministers are to meet with the Northern Ireland Secretary on the issue tonight.

PSNI Chief Constable Sir Hugh Orde (left) said the killing would not affect how the PSNI responded to incidents and it would continue to deliver its service to the community.

He said: ‘We are used to being attacked, but we will not step back. It is a sad day for the Police Service of Northern Ireland.

‘Today a police officer with his colleagues responding to a call for help from a vulnerable person in the community was gunned down.

‘This will not put off me or my officers delivering the service we do to the communities we are paid to protect. That will continue unrelenting, as it has done in the threat that we have been facing for nine to 12 months.

‘We will continue to deliver that service regardless of the threat but mindful of it.’

The Chief Constable spoke with Garda Commissioner Fachtna Murphy this morning, with Commissioner Murphy promising that gardaí would continue the current levels of co-operation.

Mr Murphy added: ‘The murders carried out in the last number of days in Northern Ireland represent a serious attack on the fundamentals of democracy itself.’

The Commissioner said he was due to meet the Chief Constable next Thursday, where recent events will be high on the agenda.

Gordon Brown has condemned the killing and said: ‘There will be no return to the old days.

‘These are murderers who are trying to distort, disrupt and destroy a political process that is working for the people or Northern Ireland. They will never be allowed to destroy or undermine the political process.’

Northern Ireland’s First Minister and DUP leader Peter Robinson said he was sickened at the attempts by terrorists to destabilise the community.

He said those responsible would not be allowed to drag the community back to the past.

Deputy First Minister Martin McGuinness has said those responsible for the attack were traitors.

Mr Robinson and Mr McGuinness were on their way back to Northern Ireland from London, and have again deferred their planned departure for the US.

Northern Ireland Secretary Shaun Woodward said the renewed violence would not stop the peace process.

‘When Northern Ireland was de-militarised, it was a normal society. We don’t want to go back,’ he said.

‘What paramilitaries have done for 40 years in the name of Ireland has been to militarise that part of Ireland and put whatever unity of the island further and further away.’

President Mary McAleese expressed her outrage saying those who carried out the killing and that of the two soldiers were acting in utter defiance of the clearly expressed will of the Irish people.

Local Sinn Féin Assembly member John O’Dowd (left) said the shooting was wrong and would not advance the goals of republicans.

Fine Gael Leader Enda Kenny TD said: ‘This murder is a despicable outrage by a tiny minority which is determined to undermine civil society.

‘This miniscule group of people cannot and will not be allowed to destroy the peace that everyone in society benefits from.’

SDLP MLA and Policing Board member Dolores Kelly said the PSNI needed the support of the community to tackle those who wanted to turn back the clock.

Ulster Unionist deputy leader Danny Kennedy said people would not allow themselves to be dragged back to a darker, bloodier world.