A 17-year-old male was charged on Thursday with the murder of three girls and the attempted murder of 10 more people in a knife attack at a Taylor Swift-themed dance class, UK prosecutors said.
The Crown Prosecution Service (CPS) said it had authorised Merseyside Police to charge the suspect with three counts of murder over the deaths of Bebe King, six, Elsie Dot Stancombe, seven, and Alice Dasilva Aguiar, nine.
The suspect will appear at court in Liverpool, in northwest England, on Thursday.
The town of Southport, where Monday's tragedy unfolded, was still reeling from the attack, and from violent clashes that broke out on Tuesday.
Bottles were thrown at police officers and several people were arrested at the rally, which police blamed on supporters of the far-right English Defence League (EDL), who it said had travelled from outside the area to the seaside town near Liverpool.
A 100-strong group attacked police and properties, throwing bricks at a mosque and setting vehicles and other objects on fire.
Police said 53 officers were wounded, at least eight of them seriously, and that they had arrested four suspects.
Police chief Serena Kennedy said her force was "absolutely planning" for further possible disturbances in the town, but Wednesday passed peacefully.
However, there were scuffles at a protest outside UK Prime Minister Keir Starmer's Downing Street residence, and in Hartlepool, in northeast England.
The scenes of violence have been widely condemned, with Starmer vowing that those responsible would "face the full force of the law".
Tuesday's violence erupted shortly after a vigil was held in the town centre, where hundreds fell silent in tribute to the victims of the stabbing attack that also critically injured five children and two adults.
Police have said they are not treating it as terror-related.
Hours after the attack, unverified information about the suspect's background began spreading on social media.
Far-right influencer Andrew Tate had posted a video on social media, viewed by nearly 15 million people, blaming the stabbing on an "illegal migrant".
The Muslim Council of Britain said the Islamophobic backlash started with a false online rumour stoked by misinformation from a Russian news site, wrongfully associating the crime with Muslims.
"At a time of great tragedy, loss, and mourning, we must stand firm against the cynical forces of hatred and division," MCB secretary-general Zara Mohammed said.
Merseyside Police's assistant chief Alex Goss said there had been "much speculation and hypothesis" about the suspect, and that "many people who do not live in" the local area had participated in Tuesday night's violence.
"What did we do to deserve this? We've already lost our children," 53-year-old Suzanne Jerram, owner of a store that was vandalised, told AFP.
"Our community's grieving, how dare they come here to our town and do this? It's disgusting, it really is disgusting."
Shadow interior minister James Cleverly urged the government to respond "hard and fast" to the disturbances and online misinformation.
Meanwhile, Deputy Prime Minister Angela Rayner suggested the government may "be looking at" whether to proscribe the far-right EDL under anti-terror laws.
The young victims of Monday's attack were named the following day.
Alice Dasilva Aguiar died in hospital early on Tuesday, police said, after Bebe King and Elsie Dot Stancombe died on Monday.
Aguiar was the daughter of Portuguese parents from Madeira. Her family said in a tribute: "Keep smiling and dancing like you love to do our princess."
US pop star Swift said she was "completely in shock" over "the loss of life and innocence, and the horrendous trauma inflicted on everyone".
