Dissident republican group the New IRA on Tuesday admitted responsibility for killing Northern Irish journalist Lyra McKeen during rioting in Londonderry last week, in a statement to The Irish News.
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 reported by the Irish newspaper, which said the paramilitary group used a recognised codeword.
McKee, 29, was shot in the head late Thursday as dissident republicans clashed with police in the Creggan housing estate in Northern Ireland's second city, also known as Derry.
While admitting responsibility, the New IRA attempted to justify its actions by claiming she was killed during an attack on "enemy forces" and accused police of provoking the riot which preceded her death.
"In the course of attacking the enemy Lyra McKee was tragically killed while standing beside enemy forces," the statement said.
"On Thursday night, following an incursion on the Creggan by heavily armed British crown forces which provoked rioting, the IRA deployed our volunteers to engage," the New IRA statement said, according to The Irish News.
In the wake of her death, Northern Ireland's six main political parties - including rival unionists and republicans who have been unable to form a devolved government for more than two years - issued a rare joint statement.
"It was a pointless and futile act to destroy the progress made over the last 20 years, which has the overwhelming support of people everywhere," it read.
The killing, the latest upsurge in violence to shake the troubled region, came in the run-up to Easter weekend, when republicans opposed to the British presence in Northern Ireland mark the anniversary of a 1916 uprising against British rule.
A car-bombing and the hijacking of two vans in Londonderry earlier this year were also blamed on a dissident paramilitary group.
The 1998 Good Friday peace deal largely brought an end to three decades of sectarian bloodshed between republican and unionist paramilitaries, as well as British armed forces, in a period known as "the Troubles".
Some 3,500 people were killed in the conflict - many at the hands of the Irish Republican Army (IRA).
The group called a final ceasefire in 1997 and announced an end to its armed campaign in 2005, stating that it would seek to achieve its aims through peaceful political means.
The New IRA is one of a number of dissident republican paramilitary groups opposed to the shift towards non-violent tactics to bring about a united Ireland.
There have been concerns that paramilitaries could be seeking to exploit the current political turbulence over Northern Ireland and its border with the Republic of Ireland caused by Brexit.