The Garda Public Order Unit was stationed outside Leinster House late on Thursday evening as they responded to unprecedented scenes.
Buses and trams have been torched and a shop looted during riots in Dublin city centre after a woman and three young children were injured in a knife attack near a school.
Gardaí and politicians called for calm amid warnings against misinformation as violence escalated from a demonstration that began on Thursday afternoon at the scene of the incident.
There were clashes with riot police as some demonstrators let off flares and fireworks, while others grabbed chairs and stools outside bars and restaurants.
A cordon was set up around Leinster House, and officers from the Garda Mounted Support Unit were in nearby Grafton Street.
Minister for Justice Helen McEntee labelled the scenes “intolerable” and said a “thuggish and manipulative element must not be allowed to use an appalling tragedy to wreak havoc”.
Garda Commissioner Drew Harris said a “complete lunatic faction driven by far-right ideology” was behind the disorder.
The violence broke out after three young children and a woman were attacked in Parnell Square East in the north of the city centre on Thursday afternoon.
A five-year-old girl was undergoing emergency treatment for her injuries, gardaí said.
The woman was seriously injured while the two other children, a five-year-old boy and a six-year-old girl, suffered less serious injuries.
Gardaí said a man who sustained serious injuries is a person of interest in their investigation.
Earlier on Thursday, Garda Superintendent Liam Geraghty said officers were keeping an open mind in terms of the investigation but were “satisfied there is no terrorist link”.
However, at an evening press conference Mr Harris was asked about a potential terrorist link, and said: “I have never ruled out any possible motive for this attack… all lines of inquiry are open to determine the motive for this attack.
“Until we’re sure what the motive is then we have to keep an open mind as to why this happened.”
The scene of the incident is close to Irish language medium primary school Gaelscoil Cholaiste Mhuire.
A Garda public order unit was deployed in the area around Parnell Square and O’Connell Street just before 7pm as protesters started to scuffle with officers and flares and fireworks were thrown at the Garda cordon.
As the violence escalated, a Garda car was set alight, a Luas tram and several buses on O’Connell Street were set on fire, and a bus and car were torched on O’Connell Bridge.
Rioters looted a Foot Locker store in O’Connell Steet as bottles were thrown at gardaí on the famous Dublin street.
In a series of co-ordinated presses, gardaí dispersed a large portion of the crowd on to nearby roads.
Smoke from bus and car fires filled the air while a Garda helicopter monitored the situation from overhead.
Dublin Fire Brigade responded to a large fire that had engulfed a Luas tram on O’Connell Street, which appeared to have spread to buses parked nearby.
Ms McEntee said: “A thuggish and manipulative element must not be allowed to use an appalling tragedy to wreak havoc.
Please be advised that all Luas services have been suspended due to a non Luas related safety incident at Parnel Street.
Apologies for any inconvenience caused.— Luas (@Luas) November 23, 2023
“I have spoken to local TDs from all sides of the Dáil and we are of the same view. We will not tolerate a small number using an appalling incident to spread division.
“I would appeal for calm in the city centre as An Garda Síochána carry out their work – attacks on members of An Garda Síochána must be utterly condemned and will be dealt with severely.
“Most importantly, we must remember the real tragedy of today and allow the investigations take their course.”
Speaking to media at Mountjoy Garda Station on Thursday evening, Mr Harris called for calm and spoke out against the spreading of misinformation.
He confirmed that a number of Garda vehicles had been damaged.
He said some individuals were using a tragic event which is under investigation “for their own ends… and a hooligan faction who are only interested in causing damage and mayhem in the city centre and they’re using the opportunity for that as well”.
“I think there’s disgraceful scenes in terms of a major investigation, the maintenance of a scene and the gathering of evidence,” he said.
“We have a complete lunatic hooligan faction driven by far-right ideology, and also then this disruptive tendency engaged in serious violence.
“We are drafting in resources to deal with that and that will be dealt with properly. I’ve given full direction to our resources here in respect of making arrests and bringing offenders to justice.
“It’s our responsibility to make sure that we police the streets, and part of that is we ask people to act responsibly and not to listen to the misinformation and rumour that is circulating on social media.
“The facts are being established, but the facts are still not clear and a lot of the rumour and the innuendo is being spread for malevolent purposes.”
Mr Harris said the motive for the afternoon attack “is not clear to us at this moment in time”.
Earlier, Mr Geraghty said: “Preliminary indications are that a male attacked a number of people on Parnell Square East.
“Five casualties have been taken to hospitals in the Dublin region. These casualties include three young children, an adult female and an adult male.
“One girl, aged five years, has sustained serious injuries and is currently receiving emergency medical treatment in CHI Temple Street.
“The male in his 50s is a person of interest to An Garda Síochána in this investigation and An Garda Síochána is not looking for any other person at this time.”
The officer said he believed a knife was used, adding: “It would appear to be a standalone attack, and we need to determine the reasons behind that.
“My understanding is members of the public did intervene at a very, very early stage and we would applaud those members of the public for getting involved in such a traumatic and potentially dangerous situation for themselves.
“We’re aware that the public are concerned about the activities that have happened today. The message to them is that we believe that this is a standalone incident, not necessarily connected to any wider issues that are ongoing in the country or in the city, and we need to identify the exact reasons for that happening.
“So we’d ask for people not to jump to conclusions and not to make rash judgments on what may have happened.”
Taoiseach Leo Varadkar said: “We are all shocked by the incident which has taken place in Parnell Square.
“A number of people have been injured, some of them children. Our thoughts and our prayers go out to them and their families.”
