What police later identified as far-right protesters then took to the streets of Dublin, setting vehicles ablaze and clashing with police.
“What we saw last night was an extraordinary outbreak of violence,” Police Commissioner Drew Harris told reporters on Friday. “These are scenes that we have not seen in decades.”
He said that 34 people had been arrested.
Police blamed a “lunatic, hooligan faction driven by a far-right ideology” for the violence that broke out after a small group of anti-immigrant protesters arrived at the scene of the knife attack.
The “riotous mob” caused “huge destruction” in Dublin, police said, with some wielding metal bars. Rioters smashed windows and looted shops as they stormed through the city.
The Dublin Fire Brigade on Friday morning said firefighters were continuing to dampen down smoldering vehicles.
Police said they weren’t looking for anyone else involved in the knife attack and were “keeping an open mind” about any motive.
Irish Prime Minister Leo Varadkar told reporters said that those involved in the riots “brought shame on Ireland.”
