Violent clashes broke out in Ireland's capital on Thursday evening, after three young children were injured in a knife attack outside a school earlier in the day.

Two adults — a woman and the suspected perpetrator of the attack — were also taken to hospital after the incident, which took place at around 1:30 p.m. local time (1330 GMT) in Parnell Square, in the city center. 

Irish police initially said they were confident the incident was not terror-related and appeared to be a standalone attack.

"[Police are] satisfied from our inquiries that there is no terror-related activity... in relation to this matter. It would appear to be a standalone attack, and we need to determine the reasons behind that," Police Superintendent Liam Geraghty told reporters.

Later, police chief Drew Harris reversed course and said he had "never ruled out any possible motive for this attack." Harris added: "I'm not going to speculate any further in respect of a terrorist motive. Until we're sure what the motive is, we have to keep an open mind as to why this happened."

Riots break out as Irish youth chant anti-immigrant slogans, loot stores

Harris also warned against the spread of "misinformation" after reports that the attack was carried out by a foreign national led to "disgraceful scenes," in which protesters clashed with police, damaging police cruisers and setting buses and police vehicles on fire.

Harris said the disorderly situation, which included wanton looting and attacks on police, had been brought about by a "complete lunatic faction driven by far-right ideology."

Videos on social media showed large groups of mostly masked Irish males chanting anti-immigrant slogans and burning public property such as trams and city vehicles.

All public transport was temporarily shut down in the city.

Crowds were also seen reportedly setting fire to an immigration center and breaking into a Foot Locker store to steal shoes.  

Police blamed right-wing extremists for the escalating situation and told Irish public broadcaster RTE that they had called in reinforcements to gain control of the situation.

Irish leaders condemn rioting

Irish Justice Minister Helen McEntee said of the day's events: "The horrific attack today in Dublin city center was an appalling crime that has shocked us all. However, the scenes we are witnessing this evening in our city center cannot and will not be tolerated. A thuggish and manipulative element must not be allowed to use an appalling tragedy to wreak havoc."

Speaking on RTE in the evening, McEntee said police had made "many arrests, there will continue to be arrests," adding, "they're thugs, they're criminals, that is exactly how they will be treated." 

President Michael D. Higgins issued a statement on the attack late Thursday evening as well, calling it "horrific" and offering prayers for the victims' full recovery. Higgins said police deserved the support of the public and labeled attacks on the principle of social inclusion, "reprehensible" and deserving of "condemnation by all those who believe in the rule of law and democracy."

Police call Dublin attack 'a very serious incident'

On Thursday afternoon, Varadkar said he had been shocked by the stabbing and announced that a suspect had been taken into custody.

The suspected attack took place near a local elementary school.

Police had cordoned off the area, and emergency services were at the scene, which is adjacent to O'Connell Street, a main thoroughfare. 

Police said officers had responded to "a very serious incident." A spokesperson said the victims included a 5-year-old girl who sustained "serious" injuries," and two more children who were treated for "less serious" injuries.

An adult female in her thirties also sustained "serious" injuries, whereas the adult male's injuries were "less serious."

The individual, said to be in his fifties, is thought to have been the perpetrator of the crime.

It has been reported that several pedestrians initially disarmed and detained the attacker before police arrived at the scene.

"The emergency services responded very quickly and were on site within minutes. I thank them for that," said Prime Minister Varadkar.

js, sdi/sms, ab (dpa, Reuters, AFP)