The New IRA has admitted responsibility for the killing of 29-year-old journalist Lyra McKee, according to an Irish newspaper.
In a statement given to The Irish News using a recognised code word, the group offered “full and sincere apologies” to her family and friends.
Ms McKee was shot in the head while she observed rioting in Londonderry’s Creggan estate on Thursday night.
The New IRA said she was killed “while standing beside enemy forces”.
In a statement to The Irish News admitting responsibility for the killing, the dissident republican group said: “In the course of attacking the enemy Lyra McKee was tragically killed while standing beside enemy forces,
“The IRA offer our full and sincere apologies to the partner, family and friends of Lyra McKee for her death.”
The group also accused police of “provoking” the rioting that preceded the gun attack that killed Ms McKee.
“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,” it said.
It added that it had “instructed our volunteers to take the utmost care in future when engaging the enemy, and put in place measures to help ensure this”.
The statement comes after the hard-left republican political party Saoradh – which has the support of the New IRA – had previously sought to justify the use of violence on Thursday.
Ms McKee was standing near a police 4×4 vehicle when she was shot after a masked gunman fired towards police and onlookers.
A protest by friends of Ms McKee took place on Monday outside an office in Derry used by dissident republican political groups.
A number of women smeared red paint in hand prints on republican slogans outside the office.
Police were present but did not make any immediate arrests.
Police said the public response to the killing had been “massive”.
Det Supt Jason Murphy said there had been a “palpable change” in community sentiment in support of their investigation, in terms of off-the-record intelligence.
He has urged members of the public to “come forward and have a conversation with me”.
It is understood that police and the Public Prosecution Service have discussed what measures could be available to protect witnesses fearful of giving evidence at trial.
Ms McKee’s killing came 21 years after the Good Friday peace agreement was signed in Northern Ireland.
The 1998 peace deal marked the end in the region of decades of violent conflict – known as the Troubles – involving republicans and loyalists during which about 3,600 people are estimated to have died.
The Good Friday Agreement was the result of intense negotiations involving the UK and Irish governments and Northern Ireland’s political parties.
Ms McKee’s funeral will be held at St Anne’s Cathedral in Belfast on Wednesday.
Her partner, Sara Canning, said the service would be a “celebration of her life”.