A new breed of terrorist is coming through the ranks in Northern Ireland, the detective leading the hunt for Lyra McKee’s killers said.

Police have arrested two teenagers who they suspect are members of the dissident republican New IRA and were involved in shooting dead the promising young journalist in Londonderry.

Police Service of Northern Ireland (PSNI) detective superintendent Jason Murphy said terrorists were lurking in the shadows.

“What we are seeing is a new breed of terrorist coming through the ranks and that for me is a very worrying situation.”

He said there had been a sea change in community attitudes and that was demonstrated in the revulsion expressed by many at Thursday evening’s killing.

A gunman aiming to kill police shot Ms McKee in the head after he fired indiscriminately during disturbances in the Creggan estate.

DS Murphy said: “There is a real sense after what happened to Lyra of a sea change and I want people to have confidence to come forward and help us.”

He added: “The individuals responsible for Lyra’s murder continue to hide in the shadows.”

DS Murphy also said they had offered no explanations for their actions to her family but police were working to bring about positive change for the community in the Creggan estate where she died.

“This will be Lyra’s legacy.

“Lyra’s murder was not just an attack on Lyra, it was an attack on the fabric of this community.

“Lyra’s killers have succeeded in only one thing, and that is in uniting the entire community in condemnation.”

He said his officers had identified “palpable” change in support of the police.

The officer appealed for anyone with information to contact detectives.

He added: “This morning we arrested two young men aged 18 and 19.

“I believe both of those are members of the New IRA, I believe both were involved in the attack on Lyra.

“Clearly my consideration is whether those two individuals acted in isolation or in collusion with other individuals, and I am keen for the community to come forward and help me answer that question.”

He said there was still fear of reprisals from the shadowy figures for giving information.

“Individuals continue to exert influence over communities, not just in the Creggan but in other parts of the communities as well.

“This intimidation and fear creates a real concern for local residents to come and talk to us as police officers.”

He said helping police with their inquiries was still unfortunately a difficult thing for some to do, but he said officers would behave sensitively.