Protests broke out in central Dublin on Thursday evening after Irish police said a 5-year-old girl was receiving emergency medical treatment following an attack that involved a knife. A woman and two other children were injured.
Irish police said they weren't treating the case as terror-related, and that a man in his 50s, who was also hospitalized with serious injuries, is a "person of interest."
Police said they have a "definite line of inquiry" and that they weren't looking for anyone else in connection with the violence outside a school in the heart of Dublin soon after 1:30 p.m.
In the early evening, protesters fired flares and fireworks at the police cordon in Dublin around the scene of the incident. Police armed with shields fended off violent demonstrators attempting to kick and punch them. Many of those attacking the police had their faces covered.
A number of police vehicles and a tram were damaged during the disorder in the city center. A bus and car were also on fire on the city's O'Connell Bridge.
"The scenes we are witnessing this evening in our city center cannot and will not be tolerated," said Justice Minister Helen McEntee. "A thuggish and manipulative element must not be allowed to use an appalling tragedy to wreak havoc."
Earlier, Superintendent Liam Geraghty said at a media briefing that preliminary indications are that a man attacked a number of people on Parnell Square East.
He said that police believe that it was "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."
Geraghty confirmed earlier witness reports that a knife was used in the attack, but he couldn't provide more details on the nature of the injuries. He also confirmed that witnesses sought to disarm the man as soon as they saw what was going on.
"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," Geraghty said.
He said that the woman, who is in her 30s, suffered serious injuries, while the two other children, a 5-year-old boy and a 6-year-old girl, sustained less serious injuries. The boy has been discharged from a hospital, he added.
