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 they suspect are members of the dissident republican New IRA involved in shooting dead the promising young journalist in Londonderry on Thursday night.

A gunman aiming to kill police hit the talented 29-year-old in the head. He fired indiscriminately during disturbances in the Creggan estate.

Floral tributes have been piling up at the lamppost where she fell, including one written to “beautiful Lyra” from her partner Sara Canning.

A close friend said her death leaves a void which will never be filled, but she hopes it will bring an end to gun violence in the city and meet the expectations of the victim’s peace process generation.

Police Service of Northern Ireland (PSNI) Detective Superintendent Jason Murphy said terrorists are lurking in the shadows, frightening and holding to ransom those they claim to represent.

He said: “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 has been a sea-change in community attitudes towards the gunmen, demonstrated in the revulsion expressed by many at Miss McKee’s killing.

The New IRA is an amalgam of armed groups opposed to the peace process and it recently claimed responsibility for parcel bombs sent to London and Glasgow in March.

Mr Murphy conceded there remains fear of reprisals for giving information to police from the shadowy gunmen.

He said: “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.

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

He said her murder was not just an attack on Miss McKee, but on “the fabric of this community”.

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

Tributes have been left where Miss McKee died (Michael McHugh/PA)

Standing beside the pile of floral tributes, Miss McKee’s friend Kathleen Bradley said she was a breath of fresh air when she moved from Belfast to the city to be with her partner.

Ms Bradley said: “Lyra’s legacy, I think, will be opening all our eyes to what we should have got as a result of the Good Friday Agreement – the ceasefire baby’s generation.

“Lyra’s legacy will be in this town that guns don’t solve anything, guns should never be used for anything, and her legacy will be that we will keep her name and spirit going amongst us.

“A very clear message has been given from not only the people of this town but wider afield to say that this is not okay, this is not acceptable, this is not justifiable.

“It has to stop, nothing is worth a life – nothing.”

The floral tribute left by Ms Canning read: “My beautiful Lyra, our time together was too short, and your light was snuffed out too soon.

“I love you forever, your Sara xxx.”

Londonderry unrest
Northern Ireland Secretary Karen Bradley has signed the book of condolence to Miss McKee (Brian Lawless/PA)

Northern Ireland Secretary Karen Bradley was among those signing a book of condolence opened at the city’s Guildhall, describing her death as a “tragic loss” of one with such potential.

Police believe the violence was orchestrated in response to an earlier search by officers aimed at averting imminent trouble associated with this week’s anniversary of the Easter Rising.

Around 50 petrol bombs were thrown in the confrontation and two cars were burned out.

Former US president Bill Clinton, whose administration played an integral peace process role, tweeted: “Heartbroken by the murder of Lyra McKee and the violence in Derry.

“The challenges in Northern Ireland today are real – but we cannot let go of the last 21 years of hard-won peace and progress. This tragedy is a reminder of how much everyone has to lose if we do.”

The EU’s chief Brexit negotiator Michel Barnier said the murder was “a reminder of how fragile peace still is in Northern Ireland”, adding: “We must all work to preserve the achievements of the Good Friday Agreement.”