The killing of two soldiers at an army base in Northern Ireland will not derail the peace process, British Prime Minister Gordon Brown said Sunday.

Police forensic officers examine the scene at the army base in Antrim, northwest of Belfast, on Sunday after two British soldiers were shot to death and four other people wounded in an ambush blamed on IRA dissidents. (Peter Morrison/Associated Press)

Brown also extended his condolences to the soldiers' families and vowed the assailants would be caught. Two men armed with assault rifles opened fire on the British soldiers at the entrance to the Massereene army barracks in Antrim, 25 kilometres northwest of Belfast, on Saturday night.

Four people were wounded, including two men delivering pizzas. Police Chief Supt. Derek Williamson said at least one of the gunmen got out of a car and shot the soldiers again at close range.

A brigade of the Real IRA republican splinter group claimed responsibility for the killing, Reuters reported Sunday. The group was formed in 1997 when it split from the mainstream Irish Republican Army, whose political wing Sinn Fein had entered talks to end sectarian violence in Northern Ireland.

The soldiers who died, both in their early 20s, were due to fly to Afghanistan in the coming days, the BBC reported.

In London, Brown said "the whole country is shocked and outraged at the evil cowardly attack."

"I assure you that we will bring these murderers to justice," he said. "No murderer will be able to derail a peace process that has the support of the people of Northern Ireland. We will step up our efforts to make the peace process one that lasts and endures."

The head of the Irish nationalist party Sinn Fein on Sunday also condemned the attack as "wrong and counter-productive."

"Those responsible have no support, no strategy to achieve a United Ireland," Sinn Fein President Gerry Adams said in a statement.

More than 4,000 British troops continue to be housed in 10 bases in Northern Ireland, but since July 2007 they have been restricted from playing any role in the province's security and are rarely seen in uniform in public.

Adams said the assailants were seeking to bring British soldiers back onto the streets and renew conflict between the British Protestant majority and Irish Catholic minority.

Both sides vowed that the attack would not undermine their 22-month-old coalition, the central accomplishment of a 1998 peace accord for the British territory following three decades of bloodshed that claimed 3,700 lives.

With files from the Associated Press