Dissident republican group the New IRA yesterday took responsibility for killing Northern Irish journalist Lyra McKee last week as police said they had arrested a 57-year-old woman in connection with the shooting.

The New IRA "offer our full and sincere apologies to the partner, family and friends of Lyra McKee for her death," it said in a statement to The Irish News. The newspaper said the paramilitary group used a recognized code word, an established method of communication during the decades of sectarian conflict in Northern Ireland known as "The Troubles."

McKee, 29, was shot in the head last Thursday as dissident republicans clashed with police in the Creggan housing estate in Northern Ireland's second city Londonderry, also known as Derry. The incident came after a car bomb blast in Northern Ireland in late January amid uncertainty over the future of the Irish border, as Brexit is adding to tensions in Northern Ireland. The New IRA was blamed for the car bombing. It is regarded as the largest of the splinter dissident groups still operating and has been linked to several other killings in the past decade. The IRA and most other militant groups have disarmed since Northern Ireland's 1998 peace accord. The New IRA has been formed from splinter groups opposed to the peace process.