Northern Ireland’s police chief has blamed the so-called “New IRA” as the primary dissident republican group orchestrating rioting and murder bids on his officers in Londonderry.

George Hamilton said members of other violent extremist dissident organisations were also involved in fomenting six successive nights of violence in Derry’s Bogside.

In the latest bout of unrest, two explosive devices were hurled at officers on Thursday night, with 74 petrol bombs also thrown.

Police have said it was a “miracle” no officers were injured.

Three men were arrested, one on suspicion of attempted murder. One, aged 50, was later charged with disorderly behaviour.

Riot police fired four baton rounds during the disturbances in the republican neighbourhood.

Many of those engaging in the violence are youths, some not even in their teens.

Hundreds of people attended a community rally in Derry on Friday evening as people demonstrated their collective opposition to the disorder. The Bishop of Derry told those in attendance that the city would not be drawn back to the years of suffering and loss.

The area remained quiet on Friday evening, with no sign of fresh disorder by 11pm.

After being briefed by local commanders in Derry earlier in the afternoon, Mr Hamilton warned that if the violence continued it was “only a matter of time” before someone was killed.

“We believe violent dissident republican groups are behind this, they will use whatever excuse they can to bring about unrest and to have young people involve themselves in violence against the police,” he said.

“We believe there are members of a variety of dissident groupings in this disorder – the so-called New IRA is probably the primary grouping behind this disorder and behind these threats to police and these murderous attacks on police.

“If this continues, it’s only a matter of time before a police officer or a child or young person involved in this violence gets very seriously injured or worse.”

The latest night of disorder flared after the city hosted Twelfth of July Orange Order parades.

Members of the public were also targeted in the violence.

At one point, a hooded rioter hurled a petrol bomb at the windscreen of a van passing through the Bogside from point blank range.

The majority of the missiles were aimed at police stationed on the historic city walls overlooking the Bogside and on Fahan Street leading to the city centre.

Large groups of hooded teenagers lined the streets of the Bogside from 9pm, carrying petrol bombs in shopping bags before starting a makeshift bonfire at the bottom of a busy flyover, in an apparent attempt to goad police into the area.

During a press conference, Mr Hamilton was challenged on why police were seemingly reluctant to deploy officers into the Bogside during the rioting.

He said those behind the violence were trying to draw police in.

“We don’t want to be fighting with anyone, we use balanced judgment when to go in and when to stay out and operational decisions are made on a routine basis,” he said.

“I’m not saying we always get it right but we certainly won’t condone unlawfulness, we will pursue those who break the law and bring them before the courts.”

He also defended the use of baton rounds, highlighting that only four had been discharged in comparison with 200 petrol bombs being hurled at officers over the last week.

Thursday’s bomb attacks represented the third murder bid against police officers in Derry this week.

On Tuesday night, a volley of machine gun fire was directed at officers and on Wednesday night two pipe bombs were thrown at police.

No-one was injured.

As well as police, rioters have also targeted homes in the nearby unionist Fountain estate.

Sinn Fein president Mary Lou McDonald, who held talks with community leaders in the city on Friday, said the rioters would not break the people of the Bogside.

She said the dissidents were on the “road to nowhere” and rejected any suggestion they were true republicans.

“What we are witnessing here is a cynical and calculated manipulation of young children into a warped agenda that serves no useful purpose,” she said.

“This is a deliberate strategy by those who style themselves as dissidents to mislead children and cause fear and hardship across the community.”

Mrs McDonald said many residents felt the police could be doing more to proactively protect the community.

“We will meet with Chief Constable George Hamilton this afternoon and we will relay the concerns of the community, but make no mistake who the instigator here is,” she added.

“A dissident element who are behaving in a manner that no person at any stage could describe as republican behaviour.

“This is the city of Martin McGuinness, of John Hume, and of civil rights, and these communities will not be broken by those on a road to nowhere.”

Earlier, Democratic Unionist leader Arlene Foster tweeted: “Really disturbing scenes last night in Londonderry. Someone will be killed if this continues. The main Party Leaders have jointly called for rioting to end. The police are risking life & limb trying to tackle this. All violence must be condemned.”

There were also scenes of violence in Belfast this week, with loyalists blamed for disorder on Wednesday night.

Masked men hijacked and torched vehicles amid anger about moves to reduce the size of two loyalist Eleventh Night bonfires.

Thousands of Orange Order members took part in Twelfth of July parades across Northern Ireland on Thursday to mark the 1690 victory of Protestant King William of Orange over Catholic King James II at the Battle of the Boyne.

The Police Federation, the body that represents rank-and-file PSNI officers, described the dissident republicans involved as a “pitiless, heartless bunch of cowards”.

Northern Ireland Secretary Karen Bradley said: “The disorder in Derry/Londonderry last night, including targeted attacks on police vehicles and others, was completely unacceptable. These sustained attacks have been widely condemned and must end.

“My full support goes to the PSNI and others who are working so hard to end this intolerable violence by a small minority.”