More people will be arrested and prosecuted as part of the investigation into the violence and riots in Dublin last week, the Garda Commissioner has said.

Drew Harris also told a policing committee that the role of far-right online instigators is being investigated as part of a wide-ranging inquiry into the events last Thursday.

He told the Dublin City Joint Policing Committee that the far right is "nebulous" and not like a transnational organised crime gang and that they are careful "not to cross the line".

The Garda Commissioner also rejected assertions by city councillors that gardaí had been "caught out" last week.

Mr Harris said they already had additional public order officers on the streets in Dublin since September and that from 6pm last Thursday, there was a "huge mobilisation" and "a rapid response" with a tenfold increase in the number of public order officers.

The investigation into the 'Love Ulster' riots in 2006 took 18 months and 119 people were arrested, he said.

He said there "will be more perpetrators with this" when there is more digital evidence, but in the meantime, these individuals remain at large and still remain a risk of crime, disorder and hate crime.

Mr Harris said the investigation was threefold, one into the stabbing of the children and their carer, one into the violence on the streets and the third into the online activity.

Independent Councillor Mannix Flynn told the Commissioner that both he and the Minister owe the people of Dublin an apology.

He said the gardaí had been previously warned about the behaviour of criminals, racists and hate speakers and that "anyone from the gardaí looking at this stuff could have seen that".

Mr Flynn accused garda management of having "no leadership, no equipment," with garda cars parked "willy-nilly".

He said he was not looking for resignations but said "the people were left high and dry".

He also said there was no leadership from Dublin City Council either, with no public transport or directions to hotels and safe places for people caught up in the violence in the city.

Garda Commissioner Drew Harris has appeared before the Dublin City Joint policing committee

Mr Harris said social media was actively monitored from an intelligence and investigative point of view during the riots last week.

He said very serious disinformation was put online over a seven to eight-hour period.

Some companies were fast at responding and taking offensive material down but he said it was "a constant battle".

Mr Harris also said that 370 officers are now trained in public order policing, an increase of 150.

Gardaí were first responding to a stabbing but the escalation was in respect of those who arrived to abuse gardaí and to show an element of hate in their speech, he said.

Mr Harris also said he had to be careful what he said about this because gardaí are investigating individuals and seeking to prosecute them.

"We know what we are doing," he said and added "it was atrocious, some people did take advantage, others mobilised for criminal damage and looting".

Mr Harris said: "It was one of the worst situations I've seen. We did go door to door that night to make sure people were not trapped in shops.

"It was an organisational mobilisation in short order, a whole of organisation response."

He also said that "so much violence and suffering is available on social media" that it is "contributing to people’s perception".

Riots were 'careless in concealing their identities'

The Garda Commissioner said more people will be arrested and prosecuted as part of the investigation into the riots.

Mr Harris said that some of the rioters and looters were "very careless in concealing their identities".

He said gardaí have harvested "good quality CCTV" from all over the city and were working to identify as many as possible.

He also accepted that garda visibility was a problem in Dublin City Centre.

"It's very clear we have to make visibility more and more sustainable," he said, "but we are also trying to manage more and more socio-economic problems," Mr Harris said.

He accepted that some people have no respect for gardaí but described them as "a vocal minority".

The job of a garda is difficult he said because they face abuse, attack and videos being taken of them on a daily basis as occurred on Thursday night.

The city councillors commended gardaí on duty that night for their bravery and thanked them and the other emergency services.

Chief Superintendent Pat McMenamin, who is in charge of policing Dublin's north inner city, told the policing committee that the current level of policing and visibility will remain in place for the short and medium term.

He said the policing plan for Christmas will also put more gardaí on the streets.

Drew Harris said he is "very concerned" that some gardaí may feel their "hands are tied" when confronting aggressive, violent and riotous behaviour.

He said it is a garda's duty and obligation to confront those individuals with "the necessary force".

"All of us understand our obligation to protect the public," he said, "we are sworn members."

The fear of oversight and the length of internal investigations are creating what the Commissioner described as "a chill factor".

Mr Harris said he was also "acutely aware" of the "stress and strain" of the length of investigations into suspected garda wrongdoing.

On the question of him apologising, he said he as Commissioner was responsible for the performance of the organisation and "they all responded magnificently."

He rejected the "narrative" that the gardaí were "unprepared" and insisted "this was not the case".

Mr Harris said what surprised and shocked gardaí on that day was the fact that a stabbing attack was "so quickly corrupted" by individuals for their need and then by looters and rioters.

He also said he had no comment to make on Sinn Féin or the Social Democrats declarations of no confidence in his leadership of An Garda Síochána.

Additional patrols

Earlier, the committee heard that additional patrols and public order units are being deployed in Dublin city centre over the next few weeks to reassure the public that the city is safe.

Assistant Commissioner Cliona Richardson told the committee that community engagement teams were also on the ground and that gardaí will identify more people involved in the violence.

She said the intense violence was subdued in a relatively short time and a senior investigating officer has been appointed to investigate the violence, riots, looting and criminal activity.

More than 100 tasks are being carried out including harvesting thousands of hours of CCTV, taking statements from eyewitnesses, workers and gardaí and cataloguing damage to Garda vehicles, Luas, and Buses.

The Assistant Commissioner said they were "determined" not to let this go and insisted gardaí are in a position to respond to any further such incidents.

Sinn Féin reiterated to Commissioner Harris that they have no confidence in his leadership.

Councillor Daithí Doolan said the far right had been sowing the seeds of conflict, division and fear in the community for years.

They have, he said, been growing, developing and strengthening and there has not been a comprehensive response from the gardaí.

He criticised the Commissioner for what he said was "a policy of appeasement" for the far right.

Mr Doolan said the gardaí were very good at tackling and shutting down the drug gangs, but not the far right who have threatened and bullied people in their houses and people coming here to work.

He also said that the only people not in fear are white men, while women, immigrants and others are afraid.

This he described as "a failure" by the Commissioner

Dublin Lord Mayor Daithí de Róiste asked the Commissioner about the plan to make Dubliners feel safe in the city.

He said we were caught out last Thursday and the gardaí cannot police the city on overtime.

The Dublin City Joint Policing Committee is a forum where local authority and senior garda officers responsible for policing and safety in the city engage with elected and community representatives.

The violence in the city centre last Thursday is the only item on its agenda today.

Chairperson Tara Deasy said Commissioner Harris is accountable for policing the city, and people need to feel safe but they do not.

She said the failures of policing last Thursday are a management issue and even though the Deputy Commissioner along with other senior officers will attend this afternoon, the chair said it would be a much more fruitful meeting if the Commissioner attended.

Ms Deacy said they had met Commissioner Harris a few weeks ago and warned him of their concerns about the increase in far-right activity and anti-social behaviour.