A dissident Irish republican group, the Continuity IRA, claims its gunmen shot and killed a policeman in Northern Ireland.
It was the second attack in three days in the province.
The Continuity IRA and the Real IRA want an end to British rule and a united Ireland.
The policeman, named as Stephen Carroll, 48, was shot on Monday night while answering a call to a broken window in the town of Craigavon, 40km southwest of Belfast.
On Saturday, two British soldiers were shot dead in an attack claimed by the Real IRA.
Hostilities in the province ended under the Good Friday peace deal in 1998.
More than 3,600 people were killed in Northern Ireland in some 30 years of "Troubles".
British Prime Minister Gordon Brown said the latest killings would not disrupt the peace process.