Rioters who torched vehicles and looted shops in Dublin following a knife attack outside a school brought "shame" on Ireland, Prime Minister Leo Varadkar said on Friday, condemning the worst violence in decades which authorities blamed on right-wing groups.
Thursday night's unrest came after three children were injured in a stabbing near the centre of the Irish capital.
The violence -- which resulted in 34 arrests -- started when a group broke through a police cordon around the attack area in Parnell Square East, north central Dublin.
The protesters set buses and trams alight and looted shops in one of Dublin's most famous throughfares, O'Connell Street.
"Those involved brought shame on Dublin, brought shame on Ireland and brought shame on their families and themselves," a visibly angry Varadkar told reporters, describing the rioters as "criminals".
A five-year-old girl sustained serious injuries in the stabbing incident, which took place around 1:30 pm (1330 GMT) on Thursday.
Two other children and two adults -- a woman and the suspected perpetrator of the attack -- were taken to hospital with lesser injuries.
Rumours on social media about the nationality of the assailant, who police only described as a man in his fifties, helped fuel the ensuing unrest.
"They (the rioters) did not do what they did because they wanted to protect Irish people," Varadkar said. "They did not do it out of any sense of patriotism, however warped.
"They did so because they're filled with hate. They love violence. They love chaos, and they love causing pain to others," he added.
The government would use the "full resources of the law, the full machinery of the state to punish those involved in yesterday's grotesque events", Varadkar said.
New laws would be passed in the coming weeks to enable police "to make better use of" CCTV evidence, he said.
Ireland would also "modernise" laws regarding hate and incitement.
"As a country we need to reclaim Ireland. We need to take it away from the cowards who hide behind masks and tried to terrify us with their violence," Varadkar said.
Police Commissioner Drew Harris told a press conference that several officers were injured, one of them seriously, as projectiles were thrown at them.
"What we saw last night was an extraordinary outbreak of violence," Harris said.
"These are scenes that we have not seen in decades."
Harris said 34 people were arrested after "huge destruction" by the "riotous mob" with 13 shops significantly damaged or looted.
Some in the mob let off flares and fireworks while others flung chairs and stools grabbed from outside bars and restaurants.
A police cordon was set up around the Irish parliament building, Leinster House, late on Thursday night, amid concerns that the violence could spread.
Harris blamed a "complete lunatic hooligan faction driven by far-right ideology" for the disorder.
He said calm was restored in the city shortly after midnight.
Harris added that "all lines of inquiry" are open to determine the motive for the knife attack.
Irish Justice Minister Helen McEntee said the chaos was "intolerable" and that a "thuggish and manipulative element must not be allowed to use an appalling tragedy to wreak havoc".
"We will not tolerate a small number using an appalling incident to spread division," she said.
