Two adults were also stabbed and are in critical condition. Kennedy said the adults appear to be have been injured while trying to protect the children.
The Merseyside Police said they arrested a 17-year-old boy from the nearby village of Banks on suspicion of murder and attempted murder. They also recovered a knife, police said. They said the arrested youth was originally from Cardiff.
“We can also confirm that the incident is not currently being treated as terror-related, and we are not looking for anyone else in connection with the incident,” the police said.
The attack was at a small community center where primary-school-age children were attending a Taylor Swift-themed yoga and dance class. The building is down an alleyway on Hart Street, a mostly residential road of two-story brick buildings with some scattered shops.
“It is understood that the children were attending a Taylor Swift event at a dance school when the offender, who was armed with a knife, walked into the premises and started to attack those inside,” Kennedy said at the news conference. “We believe that the adults who were injured were trying to protect the children at the time they were attacked.”
Kennedy added, “As a mum of two daughters, and the nanna of a five-year-old granddaughter, I cannot begin to imagine the pain and suffering the families of the victims are currently going through, and I want to send them our heartfelt condolences and sympathies.”
The attack took place a few minutes before noon on the first day of the school holiday.
The North West Ambulance Service said it responded to “reports of multiple stabbings” with 13 ambulances and a helicopter. Emergency services crews treated 11 people at the scene. The wounded were taken to Alder Hey Children’s Hospital, Aintree University Hospital and Southport and Formby Hospital.”
The police described the attack as “ferocious.”
Tim Johnson, a journalist at Eye on Southport, told the BBC he saw a bloodied girl on a stretcher.
“Her parents were running after her. It was horrendous. I’ve never seen anything like it,” Johnson told the broadcaster.
BBC Radio interviewed a man who he said saw young girls “bleeding.” A Press Association reporter interviewed a man who said some of the victims appeared to be around 10 years old.
Other witnesses told reporters that parents were running up and down the street, wailing and screaming. Local WhatsApp groups received frenzied messages telling people to go inside and lock doors.
Prime Minister Keir Starmer described the stabbings as “horrendous and deeply shocking news.”
In a statement on X, King Charles III said: “My wife and I have been profoundly shocked to hear of the utterly horrific incident in Southport today. We send our most heartfelt condolences, prayers and deepest sympathies to the families and loved ones of those who have so tragically lost their lives, and to all those affected by this truly appalling attack.”
A motive for the stabbings was not immediately clear. The arrested youth will be interviewed by detectives, the police said, and officers were seen at the house where he is believed to live.