A senior police officer has expressed his concern at “a new breed of terrorists coming through the ranks” following the murder of journalist Lyra McKee.
The comments come after two teenagers were arrested under the Terrorism Act in connection with the killing as the reporter, 29, covered disturbances on the Creggan estate in Londonderry on Thursday night.
She was shot in the head and died later in hospital.
The men, aged 18 and 19, were held by detectives from the Police Service of Northern Ireland’s (PSNI) major investigation team and were taken to a police station in Belfast for questioning.
Detective Superintendent Jason Murphy said terrorists were “lurking in the shadows”.
He warned: “What we are seeing is a new breed of terrorist coming through the ranks and that for me is a very worrying situation.”
The officer, who is leading the investigation, said there had been a sea change in community attitudes and that it had been demonstrated in the revulsion expressed by many following the killing.
He added: “We identified a palpable change in community sentiment, particularly the community sentiment towards policing. I think yesterday we realised the vast majority of communities across the whole of Northern Ireland support police and support policing and they support the peace process.
“What we saw yesterday was a visible demonstration of that within the Creggan community, a community that has been very frightened for a long time and for a large part is being held to ransom by terrorist organisations that claim to represent them.”
The PSNI, which released CCTV of the incident in the hope it would help identify the killer, said a gunman fired shots towards police officers at about 10pm.
In her final moments, Ms McKee is seen standing among a crowd of other innocent bystanders and raising her phone in the air, apparently to photograph the violence.
In shaky mobile phone footage also released by detectives, a masked attacker leans from behind cover and appears to shoot towards police and onlookers.
Trouble began as officers carried out a search operation aimed at disrupting dissident republicans ahead of this weekend’s commemoration of Irish independence.
Officers say about 50 petrol bombs were thrown during the confrontation and two cars were burned out.
Ms McKee, who had tweeted about the “absolute madness” in the area in the hours before she lost her life, was standing near a police 4×4 vehicle when she was hit.
In the video, a figure near the gunman appears to crouch and pick something up from the spot where the shots were fired, seemingly confirming detectives’ theory that more than one person was involved.
Detective Superintendent Jason Murphy said: “The brutal nature of the attack has sent shockwaves around the world. The shots were fired in a residential area at a time when there were large numbers of local people on the street including children.
“The gunman showed no thought for who may have been killed or injured when he fired these shots.”
He also appealed for people with video footage on their phones from Thursday night to come forward.
“Lyra’s murder was not just an attack on Lyra – it was an attack on the fabric of the community,” he added. “Lyra’s killers have succeeded only in uniting the entire community in condemnation.”
On Friday evening, Ms McKee’s partner Sara Canning told a vigil in Londonderry: “Our hopes and dreams and all of her amazing potential was snuffed out by this single barbaric act.
“It has left me without the love of my life, the woman I was planning to grow old with.”
Detectives have said the New IRA, a dissident republican group, was most likely behind the reporter’s killing.
Saoradh, a political party with links to dissident militants, released a statement claiming a “republican volunteer” shot Ms McKee while attempting to “defend people” from the PSNI.
Mark Hamilton, the force’s assistant chief constable, called the killing a “horrendous act” carried out by people that “do not care who they harm”.
Prime Minister Theresa May and Taoiseach Leo Varadkar condemned the killing, while former US president Bill Clinton tweeted: “Heartbroken by the murder of Lyra McKee and the violence in Derry.”