London — British police said Thursday they’ve charged a 17-year-old with murder over a stabbing attack that left three little girls dead and several more in critical condition. The charges came as the traumatized town of Southport cleaned up after a bout of far-right violence and agitators fired up by anger and misinformation clashed with police near the prime minister’s residence in London.

The Merseyside Police force said the teenager, who hasn’t been named because of his age, faces three counts of murder and 10 of attempted murder over people injured in the attack during a Taylor Swift-themed summer holiday dance and yoga class.

He is due to appear in court in Liverpool later Thursday.

About two dozen children were attending the summer vacation workshop on Monday when an attacker with a knife burst in. Alice Dasilva Aguiar, 9, Elsie Dot Stancombe, 7, and Bebe King, 6, died from their injuries. Ten other people were injured, among whom five girls and two adults are in critical condition.

Far-right demonstrators have launched several violent protests, ostensibly in response to the attack, clashing with police outside a mosque in Southport on Tuesday.

A few hundred protesters hurled beer cans and flares near British Prime Minister Keir Starmer’s residence on Downing Street in central London on Wednesday evening. More than 100 people were arrested for offenses including violent disorder and assault on an emergency worker, London’s Metropolitan Police force said.

Police also faced violent demonstrators in the town of Hartlepool in northeast England as far-right groups seek to stir anger over an attack they have sought to link – without evidence – to immigrants.

Hours earlier, residents of Southport swept shattered glass and broken bricks from streets after far-right protesters clashed with police outside a mosque in the seaside town.

On Tuesday night, a crowd of several hundred people hurled bricks and bottles at riot police in Southport, set garbage bins and vehicles on fire and looted a store, hours after a peaceful vigil for the girls, aged 6, 7 and 9, were killed. More than 50 officers were injured, including more than two dozen who were taken to hospitals, officials said.

“I am absolutely appalled and disgusted at the level of violence that was shown towards my officers,” Merseyside Chief Constable Serena Kennedy said. “Some of the first responders who attended that awful scene on Monday … then were faced with that level of violence.”

Five men have been arrested in connection with the riots in Southport, mainly for violent disorder; one was arrested for possessing a knife and fighting. Kennedy said more arrests were expected.

Starmer condemned the “thuggery” and said the protesters “hijacked” the community’s grief.

Norman Wallis, chief executive of the Southport Pleasureland amusement park, was one of dozens of people who turned up with brushes and shovels to clear the debris.

“It’s horrendous what those hooligans have done last night,” he said. “But none of those people were the people of Southport,” he added. “The people of Southport are the ones here today cleaning the mess up.”

Misinformation’s apparent role  

The protesters, who police said were supporters of the far-right English Defence League, were apparently fueled by false online rumors about the suspect.

Police said a name circulating on social media – spread by far-right activists and accounts of murky origin purporting to be news organizations – was incorrect and that he was born in Britain, contrary to online claims he was an asylum-seeker. The names of suspects under the age of 18 are usually not made public in Britain.

Patrick Hurley, the local lawmaker, said the violence by “beered-up thugs” was the result of “propaganda and lies” spread on social media.

“This misinformation doesn’t just exist on people’s internet browsers and on people’s phones. It has real world impact,” he said.

Chanaka Balasuryla, whose corner store was looted for booze and cigarettes, said he watched from home on a surveillance camera as a gang broke in. He was terrified because a woman and her daughter lived upstairs and he feared the looters would set the shop on fire.

He learned later that the woman had confronted the mob and told them the Windsor Mini Mart was her shop and asked them to stop. The next morning he went get down to his shop were people waiting to help him clean up.

“I feel safe again because people are here to protect us,” he said.

Knife crime a growing British concern  

The rampage in Southport is the latest shocking attack in a country where a recent rise in knife crime has stoked anxieties and led to calls for the government to do more to clamp down on bladed weapons, by far the most commonly used instruments in U.K. homicides.

Witnesses described hearing screams and seeing children covered in blood in the mayhem outside the Hart Space, a community center that hosts everything from pregnancy workshops to women’s boot camps.

Joel Verite, a window cleaner riding in a van on his lunch break, said his colleague slammed on the brakes and reversed to where a woman was hanging on the side of a car covered in blood.

“She just screamed at me: ‘He’s killing kids over there. He’s killing kids over there,'” Verite told Sky News.

“It was like a scene you’d see on a disaster film,” he said. “I can’t explain to you how horrific it is what I saw.”

Britain’s worst attack on children was in 1996, when 43-year-old Thomas Hamilton shot and killed 16 kindergartners and their teacher in a school gymnasium in Dunblane, Scotland. The United Kingdom subsequently banned the private ownership of almost all handguns.

While knives are used in about 40% of homicides each year, mass stabbings are unusual.

Taylor Swift weighs in

Swift posted a message on social media Tuesday expressing her sympathy.

“The horror of yesterday’s attack in Southport is washing over me continuously, and I’m just completely in shock,” Swift wrote. “The loss of life and the innocence, and the horrendous trauma inflicted on everyone who was there, the families, and first responders. These were just little kids at a dance class. I am at a complete loss for how to ever convey my sympathies to these families.”

By Tuesday morning, a group of Swift’s fans had raised the equivalent of tens of thousands of dollars to support the victims of the attack and their families, according to CBS News partner network BBC News.

— Haley Ott contributed reporting