A Northern Ireland police officer was shot dead while on patrol on Monday, two days after Irish Republican Army dissidents shot to death two British soldiers.
The police officer was fatally shot in the head while sitting in his patrol car in the religiously divided town of Craigavon.
The Secretary of State for Northern Ireland, Shaun Woodward condemned the attack.
"This was a brutal attack and I'm afraid shows just how ruthless these criminals are, but you know we've got to remember that we know very few details about this -what we do know today is that the politicians in Northern Ireland showed a unity of purpose in the way that they rejected the violence of the weekend and I think that's first of all an example for us all."
The incident raised fears that dissident republicans are bringing violence back to the streets of Northern Ireland.
The dissident republican splinter group Continuity IRA has claimed responsibility for the incident.
The dissident Real IRA faction Saturday night shot dead two British soldiers on an army base in Antrim, west of Belfast, and injured another four people.