Three men and a teenage boy have been arrested over the Derry riots where journalist Lyra McKee was killed.

The Police Service of Northern Ireland (PSNI) said the suspects, aged 15, 18, 38 and 51, were arrested on Thursday morning under terror laws.

Detective Superintendent Jason Murphy said: “As part of this morning’s operation detectives carried out searches at four houses in the city and arrested four people in connection with the violence which was orchestrated on the streets of Creggan on the evening of Lyra McKee’s murder.

The suspects are being questioned by detectives in Belfast.

Ms McKee, 29, was shot dead as she stood next to a police vehicle in Derry on 18 April.

Violence erupts in Northern Ireland as journalist killed during riots Show all 21 1 /21 Violence erupts in Northern Ireland as journalist killed during riots Violence erupts in Northern Ireland as journalist killed during riots A burning car in Creggan, Derry after petrol bombs were thrown at police during riots in Northern Ireland PA Violence erupts in Northern Ireland as journalist killed during riots Armed police at the scene of unrest PA Violence erupts in Northern Ireland as journalist killed during riots Petrol bombs being thrown at police PA Violence erupts in Northern Ireland as journalist killed during riots Belfast Journalist Lyra McKee was killed during the riots. Police Service of Northern Ireland said that McKee was allegedly shot while reporting on clashes with dissident republican rioters EPA Violence erupts in Northern Ireland as journalist killed during riots A burning car in Creggan, Londonderry after petrol bombs were thrown at police. PRESS ASSOCIATION Photo. Picture date: Thursday April 18, 2019. Photo credit should read: Niall Carson/PA Wire Niall Carson PA Violence erupts in Northern Ireland as journalist killed during riots Armed police in Creggan, Londonderry after shots were fired and petrol bombs were thrown at police. PRESS ASSOCIATION Photo. Picture date: Thursday April 18, 2019. Photo credit should read: Niall Carson/PA Wire Niall Carson PA Violence erupts in Northern Ireland as journalist killed during riots Armed police in Creggan, Londonderry after shots were fired and petrol bombs were thrown at police. PRESS ASSOCIATION Photo. Picture date: Thursday April 18, 2019. Photo credit should read: Niall Carson/PA Wire Niall Carson PA Violence erupts in Northern Ireland as journalist killed during riots Petrol bombs are thrown at police in Creggan, Londonderry. PRESS ASSOCIATION Photo. Picture date: Thursday April 18, 2019. Photo credit should read: Niall Carson/PA Wire Niall Carson PA Violence erupts in Northern Ireland as journalist killed during riots Armed police in Creggan, Londonderry after shots were fired and petrol bombs were thrown at police. PRESS ASSOCIATION Photo. Picture date: Thursday April 18, 2019. Photo credit should read: Niall Carson/PA Wire Niall Carson PA Violence erupts in Northern Ireland as journalist killed during riots Heavilly armed police guard a crime scene during unrest in the Creggan area of Londonderry. PRESS ASSOCIATION Photo. Picture date: Thursday April 18, 2019. See PA story . Photo credit should read: Niall Carson/PA Wire Niall Carson PA Violence erupts in Northern Ireland as journalist killed during riots Hijacked vehicles on fire in Creggan, Londonderry. PRESS ASSOCIATION Photo. Picture date: Thursday April 18, 2019. Photo credit should read: Niall Carson/PA Wire Niall Carson PA Violence erupts in Northern Ireland as journalist killed during riots Armed police in Creggan, Londonderry after shots were fired and petrol bombs were thrown at police. PRESS ASSOCIATION Photo. Picture date: Thursday April 18, 2019. Photo credit should read: Niall Carson/PA Wire Niall Carson PA Violence erupts in Northern Ireland as journalist killed during riots hijacked vehicles one fire in Creggan, Londonderry. PRESS ASSOCIATION Photo. Picture date: Thursday April 18, 2019. Photo credit should read: Niall Carson/PA Wire Niall Carson PA Violence erupts in Northern Ireland as journalist killed during riots Petrol bombs are thrown at police in Creggan, Londonderry. PRESS ASSOCIATION Photo. Picture date: Thursday April 18, 2019. Photo credit should read: Niall Carson/PA Wire Niall Carson PA Violence erupts in Northern Ireland as journalist killed during riots Petrol bombs are thrown at police in Creggan, Londonderry. PRESS ASSOCIATION Photo. Picture date: Thursday April 18, 2019. Photo credit should read: Niall Carson/PA Wire Niall Carson PA Violence erupts in Northern Ireland as journalist killed during riots A hijacked car explodes after being set on fire in Creggan, Londonderry. PRESS ASSOCIATION Photo. Picture date: Thursday April 18, 2019. Photo credit should read: Niall Carson/PA Wire Niall Carson PA Violence erupts in Northern Ireland as journalist killed during riots A PSNI officer conducts a search after shots where reportedly fired in Creggan, Londonderry. PRESS ASSOCIATION Photo. Picture date: Thursday April 18, 2019. Photo credit should read: Niall Carson/PA Wire Niall Carson PA Violence erupts in Northern Ireland as journalist killed during riots The scene of unrest in Creggan, Londonderry. PRESS ASSOCIATION Photo. Picture date: Thursday April 18, 2019. Photo credit should read: Niall Carson/PA Wire Niall Carson PA Violence erupts in Northern Ireland as journalist killed during riots Police conduct a crime scene search after shots where fired in Creggan, Londonderry. PRESS ASSOCIATION Photo. Picture date: Thursday April 18, 2019. Photo credit should read: Niall Carson/PA Wire Niall Carson PA Violence erupts in Northern Ireland as journalist killed during riots The scene on Fanad Drive the following day PA Violence erupts in Northern Ireland as journalist killed during riots The scene on Fanad Drive in Londonderry, Northern Ireland, following the death of 29-year-old journalist Lyra McKee who was shot and killed when guns were fired and petrol bombs were thrown in what police are treating as a "terrorist incident". PRESS ASSOCIATION Photo. Picture date: Friday April 19, 2019. See PA story ULSTER Unrest. Photo credit should read: Brian Lawless/PA Wire Brian Lawless PA

Violence had broken out earlier in the evening, following searches in Creggan that police said aimed to disrupt planned attacks by dissident republicans.

Footage showed Molotov cocktails being launched at police vehicles and cars being set on fire in the street, before a hooded man opened fire with a handgun.

The man, dressed in dark clothing and with his head and face covered, could be seen leaning around the barrier surrounding the Creggan Day Centre to aim towards police.

He fired two shots, three seconds apart, with what appeared to be a handgun before screaming could be heard.

The suspect then left and suspected accomplices could be seen crouching to the ground where the gunman stood, potentially to pick up evidence.

Det Supt Murphy said police had received “widespread support” from the public, with more than 140 people so far coming forward with photos and footage.

“I still want to hear from anyone who can tell us anything they know,” he added.

“I would urge anyone who has any information to contact my team of detectives.”

Sara Canning, partner of murdered journalist Lyra McKee, slams Theresa May as 'derelict' in her duty to Northern Ireland

The New IRA claimed responsibility for the attack, which followed a campaign of parcel bombs sent to targets in mainland Britain and a car bombing in Derry.

The terrorist group classed the police operation in Creggan, which was to prevent violence during commemorations for the Easter Rising, as an “incursion by heavily armed British crown forces”.

“We have instructed our volunteers to take the utmost care in future when engaging the enemy, and put in place measures to help ensure this,” a statement 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 shooting shocked Derry, coming almost exactly 21 years after the Good Friday agreement was struck with the aim of bringing peace to Northern Ireland.

Pro-IRA murals have been vandalised in the city, amid protests, vigils and tributes to Ms McKee’s life and work.

At her funeral, a priest received a standing ovation after asking "why it takes the death of a 29-year-old woman with her whole life in front of her" for republican and unionist politicians to stand together.

Ms McKee worked as an editor for California-based news site Mediagazer and had freelanced for publications including The Independent.

A new mural of Lyra McKee in Belfast city centre (PA)

One piece explored the treatment of the LGBT community and Catholics in Northern Ireland and another explored the impact on sectarian violence on the “Good Friday Agreement generation” and suicides.

Ms McKee had written a book on the Troubles and had been investigating the disappearance and young men for her second book – The Lost Boys.

Her last tweet showed a photo of burning cars and police vehicles at the scene of the unrest with the caption: “Derry tonight. Absolute madness.”

Creggan, a large housing estate on the outskirts of Derry, saw frequent attacks on the British Army during the Troubles and was controlled for a period by the IRA.

Recent years have seen regeneration projects carried out but a recent report by the Institute for Conflict Research found that sectarian violence and vigilantism persists.

Last week, a republican councillor won local elections in the ward where Ms McKee was murdered.