SOUTHPORT, July 30 — An attacker with a knife killed two children and wounded 11 other people, including six youths in critical condition, at a dance class in northern England yesterday, police said.

A 17-year-old male has been arrested on suspicion of murder and attempted murder in Southport, near Liverpool in northwest England, in an attack that also left two adults with critical injuries, Merseyside Police said.

Police chief Serena Kennedy said that the attack was not being treated as terror-related, and that the attacker’s motivation was unclear.

All of those injured had been stabbed, she added.

Prime Minister Keir Starmer told the media that "the events today are just truly awful, the whole country is deeply shocked”.

"Our thoughts and condolences are with the victims, families, friends and wider community. It is almost impossible to imagine the grief,” he said.

‘Can’t imagine the pain’

Police were called to a property that was hosting a Taylor Swift-themed dance class for young children shortly before midday (1100 GMT), Kennedy said.

Officers were "shocked to find that multiple people, many of whom were children, had been subjected to a ferocious attack”, she said.

The suspect apparently walked in from the street and started to attack the children, while adults in the room tried to protect them, Kennedy said.

Armed officers arrived and detained the suspect and seized a knife.

King Charles III offered his "most heartfelt condolences, prayers and deepest sympathies” in a statement, calling the incident "utterly horrific”.

Prince William and his wife Katherine posted on X that "as parents, we cannot begin to imagine what the families, friends and loved ones of those killed and injured in Southport today are going through”, calling it a "heinous attack”.

The North West Ambulance Service (NWAS) said it treated 11 casualties with stab injuries at the scene, who were then taken by ambulance and helicopter to Alder Hey Children’s Hospital and other hospitals in the area.

Local business owner Colin Parry, one of the people who called police, told the Press Association news agency that he believed several "young girls” had been stabbed.

Bare Varathan, who owns a local shop, told PA he saw "seven to 10 kids” who were "injured, bleeding”, adding that he saw they had been stabbed.

The suspect is in custody and "enquiries are ongoing to establish the motive for this tragic incident”, police said.

The area where the incident took place is in a quiet neighbourhood of residential streets.

Some residents who were allowed to come out from the police cordon sealing it off looked shocked, according to an AFP reporter at the scene.

"It’s not what you expect to see in Southport,” one man who lives in an adjoining street, who did not wish to give his name, told AFP. — AFP