Two children were stabbed to death at a Taylor Swift-themed event in northwest England, and a 17-year-old male suspect was arrested, police said on Monday.
He was held on suspicion of murder and attempted murder. Nine other children were wounded, six of them critically, and two adults were in a critical condition.
"We believe that the adults who were injured were bravely trying to protect the children," said Chief Constable Serena Kennedy from Merseyside Police.
She said emergency services arriving at the scene found "multiple people, many of whom were children, had been subjected to a ferocious attack and had suffered serious injuries."
An advertisement posted online described the event as a yoga and dance workshop for children aged between six and 11.
Motives unclear for the attack
Merseyside Police said the motive for the attack was unclear but it was not believed to be terrorism-related and they were not looking for anyone else in connection with the stabbings.
Police said armed police had arrested the suspect and seized a knife after being called around 11:50 a.m. to an address in Southport, north of Liverpool.