Irish police have arrested 34 people after rioting in Dublin city centre on Thursday night.

Violence flared after three children and a school care assistant were injured in a knife attack in the city centre several hours earlier.

Taoiseach (Irish Prime Minister) Leo Varadkar said about 500 people were involved in the riot.

He said they “brought shame” on Ireland and promised new laws within weeks to bring those involved to justice.

Mr Varadkar added that two of the five people injured in the stabbings outside a primary school on Parnell Square were still critically ill.

They include a five-year-old girl and a school care assistant who “used her body as a shield” in a bid to protect children from the attacker.

Just hours after the stabbing, rioters destroyed 11 police vehicles, while 13 shops were badly damaged and more were looted during the clashes with police.

Three buses and a tram were also destroyed and several police officers were injured during over three hours of sustained violence.

The Dublin Fire Brigade (DFB) said a fire truck that attended the stabbing scene was later attacked by rioters.

Speaking to RTÉ on Friday, divisional organiser Geoff McEvoy said: “That truck was actually among the Dublin Fire Brigade trucks and ambulances that were first on the scene giving paramedic assistance to the victims of that stabbing that afternoon.

“Then at about 18:00, the shift changed… one of the first calls that truck responded to was a petrol bombing of a refugee centre.”

He said “the truck was pelted with projectiles” and “beaten with iron implements”.

Ireland’s police chief, Garda Commissioner Drew Harris, said there had been an “element of radicalisation” to the riot.

The “extraordinary outbreak of violence” had come after “hateful assumptions” were made based on material circulating online in the wake of the stabbings, he added.

It is understood that included false claims that the attacker was a foreign national.

Sources have indicated to the BBC that the man suspected of carrying out the attack is an Irish citizen in his late 40s who has lived in the country for 20 years.

“These are scenes that we have not seen in decades,” said Mr Harris.

“What is clear that people have been radicalised through social media.”

Under questioning from reporters, Commissioner Harris denied that his force had failed to protect Dubliners and their city from the violence.

“We could not have anticipated that in response to a terrible crime – the stabbing of school children and their teacher – that this would be the response,” he said.

Thirty-two people are due to appear in court in Dublin on Friday in connection with the riot.

The General Secretary of the Association of Garda Sergeants and Inspectors, Antoinette Cunningham, said police needed more support in Dublin and need to be supplemented by officers from outside of the city.

Speaking to RTÉ, Ms Cunningham said authorities must be challenged on how the police were resourced.

Leo Varakdar said the violence had left the nation “unsettled and afraid”.

“Yesterday we experienced two terrible attacks – the first was an attack on innocent children; the second was an attack on our society and the rule of law,” said the taoiseach.

“Each attack brought shame to our society and disgrace to those involved and incredible pain to those who were caught up in the violence.”

Mr Varadkar said the rioters’ motivation had nothing to do with Irish patriotism.

“Their first reaction to a five-year-old child being stabbed was to burn our city, attack its businesses and assault our gardaí, “he said.

The taoiseach vowed to use the “full resources of the law to punish those involved” but added that Ireland’s hate crime legislation was “not up to date for the social media age”.

“We will pass new laws in the coming weeks to enable the gardaí to make better use of the CCTV evidence they collected yesterday.

“We’ll modernise our laws against incitement to hatred and hatred in general and that is more required than ever was the case before.”

Quiet has fallen over the city but the violence went on into the early hours.

As somebody who lives in Dublin, I’ve never seen anything like this.

People are genuinely on edge, businesses are closed today and buses and the Luas tram aren’t running fully.

I don’t think Dublin has had a night like this in decades.

Eyewitness Patricia MacBride, who is originally from Londonderry, said many of the rioters were “young people – late-teens, early 20s”.

“But what was disturbing was there an older generation of people egging them on,” she told the BBC.

The knife attack took place outside Gaelscoil Choláiste Mhuire, a primary school in the city centre, after 13:40 local time on Thursday.

It is understood that a group of young children were lining up when a man carried out the stabbings, with one eyewitness describing the scene as “absolutely bedlam”.

A man in his late 40s who was also seriously injured is a person of interest, according to police.

They said they were not looking for anyone else in relation to the stabbings and were following a definite line of inquiry.

Riot police were deployed after disorder broke out near the scene of the attack, including on O’Connell Street which is one of Dublin’s main shopping streets.

Mr Harris blamed the rioting on a “lunatic, hooligan faction driven by a far-right ideology”, who engaged in violence as police tried to protect the scene of the stabbings for investigation.

In respect of the critically-injured girl, Mr Harris said: “The child herself and also her family are going through a terrible ordeal.”

Irish President Michael D Higgins condemned the attack and the subsequent disorder, which he said “deserves condemnation by all those who believe in the rule of law and democracy”.