Blow to Peace Process

The officer was shot in the head while on duty in Craigavon, 20 miles (32 kilometers) southwest of Belfast, late Monday, March 9, police said. It's the first killing of a policeman in Northern Ireland in a decade.

Police said they have arrested two males, aged 17 and 37, in the connection with the officer's murder.

The officer was killed in an apparent ambush, according to the AFP news agency. Following a callout to an incident near a nationalist republican area, two police cars raced to the scene, the agency said. Gunmen lying in wait opened fire as the officers stepped out of one of the vehicles, according to AFP.

The latest incident follows the fatal shooting of two soldiers on Saturday, as they received a pizza delivery at their army base north of Belfast.

Gunmen reportedly entered the base as the pizzas were delivered and fired up to 40 shots in two long bursts of gunfire.

Fears for political stability

The killings have raised fears that Northern Ireland's political stability is under threat. The current power-sharing government unites former arch enemies across the Protestant-Catholic divide.

"We are staring into the abyss and I would appeal to people to pull back," Dolores Kelly, a nationalist SDLP lawmaker and member of the Northern Ireland policing board, was quoted as saying by Sky News television.

Political leaders haved vowed the violence would not shake the province's progress to peace.

Northern Ireland's First Minister Peter Robinson said he was "sickened" by the attacks. Britain's Northern Ireland Secretary Shaun Woodward added: "We must not allow them the capacity to undermine the political process."

No group has taken responsibility for killing the policeman but the Real IRA, -- a dissident group of the Irish Republican Army -- said it was responsible for the shooting of the two British soldiers.

The Real IRA was also behind Northern Ireland's most deadly attack, the 1998 Omagh bombing which killed 29 people.

History of bloodshed

Northern Ireland was racked for three decades by violence which began in the 1960s. More than 3,000 people were killed in the conflict between nationalist Catholics and loyalist Protestants in Northern Ireland.

The last British military death in the conflict was in 1997 and the Good Friday Agreement was signed the following year.

In 2007, the mainly Protestant Democratic Unionists, which want Northern Ireland to remain part of Britain, and the Catholic Sinn Fein, which supports integration into the Republic of Ireland, established the present power-sharing government, which has devolved power from London.