CNN  — 

Violent clashes broke out between police and “far-right” protesters in the central part of Dublin, Ireland, on Thursday after a knife attack in the capital city earlier in the day left three children and two adults injured.

Irish police said they arrested 34 people after the riots. Speaking during a press conference Friday, Garda (police) Commissioner Drew Harris said police could “not have anticipated” that the stabbings would have triggered “such disorder.”

Harris told journalists that a 5-year-old child remains in a “very serious condition” and a female teacher is in a “serious condition.”

“These are scenes that we have not seen in decades. But what is clear is that people have been radicalized through social media,” he said. On Thursday, Harris described the rioters as “a complete lunatic hooligan faction driven by far-right ideology.”

Video on social media earlier Thursday appeared to show a group of men clashing violently with officers in Dublin and setting a police car on fire. A man could also be seen in the footage holding a sign reading, “Irish Lives Matter.” Some protesters can be heard on video chanting anti-immigrant slogans, including: “Get them out.”

People stand in front of riot police, near the scene of a suspected stabbing that left few children injured in Dublin, Ireland, November 23, 2023. REUTERS/Clodagh Kilcoyne

The clashes came after a man in his 50s was detained by police after he allegedly stabbed several people, including the girl who is receiving emergency treatment. Police have not revealed the nationality of the suspect. The incident took place in Parnell Square, in the city’s center, according to police.

The Irish police said they weren’t considering terrorism as a motive for the violence.

Speaking Friday, the police chief detailed the extent of the “huge destruction” caused by what he said was a “riotous mob,” with video showing rioters looting shops including one of Dublin’s major department stores.

According to Harris, four buses and one tram were destroyed and 11 police vehicles damaged. Thirteen shops in the city center were also seriously damaged, according to the police chief. One police officer was seriously injured in the clashes, Harris said.

A large number of rioters also tried to smash through the police cordon and “disrupt” the crime scene, he said.

A large police presence will be deployed in Dublin city center on Friday, with Harris encouraging shoppers and workers to come into the city as normal.

“We cannot allow the city to be given over to the thugs, the looters and the arsonists,” the police chief said.

European Union Commission President Ursula von der Leyen said she was “shocked” by the knife attack, according to a statement on X. Similarly, Ireland’s deputy prime minister said he was “deeply shocked by the serious incident in Dublin.”

In a statement on X shortly after the incident, Sinn Fein Leader Mary Lou McDonald said the violent attack “has sent shock and horror throughout the community.”

Ireland’s Justice Minister Helen McEntee described the protesters as “thugs” and “criminals” who were “using this appalling attack to sow division and wreak havoc in the city.”

CNN’s Sugam Pokharel and Amy Croffey contributed to this report.