Girls ages 6, 7 and 9 killed in stabbings at Taylor Swift-themed event

LONDON -- A third young girl has died following a stabbing spree at a children's Taylor Swift-themed event in the United Kingdom, police said Tuesday, as the pop star reacted on social media saying she was "in shock."

Officers responded just before noon on Monday to reports of a stabbing at a property in Southport, a seaside town about 20 miles north of Liverpool, according to Merseyside police.

Two girls, 6-year-old Bebe King and 7-year-old Elsie Dot Stancombe, were killed, and nine other children were injured, police said.

A third girl, 9-year-old Alice Dasilva Aguiar, died on Tuesday morning in the hospital, police said.

Alice was one of six wounded children who had been in critical condition, along with two adults, who were also stabbed, police said.

The other five children and two adults remained in critical condition on Tuesday, police said.

"We believe that the adults who were injured were bravely trying to protect the children who were being attacked," Merseyside Police Chief Constable Serena Kennedy said on Monday.

The motive remains unclear, Kennedy said.

Merseyside police said the children were attending a Taylor Swift-themed event at a dance school. A flyer for the two-hour event called it a "Taylor Swift Yoga and Dance Workshop." The event was for children between 6 and 11 years old, according to a post on the organizer's Instagram.

The "horror" of the attack was "washing over me continuously," Swift said in a post on Instagram. She said she was "completely in shock."

"The loss of life and innocence, and the horrendous trauma inflicted on everyone who was there, the families and first responders," she said. These were just little kids at a dance class. I am at a complete loss for how to even convey my sympathies to these families."

A 17-year-old boy from Banks, a coastal village in Lancashire, just outside Southport, was arrested on suspicion of murder and attempted murder, police said. The suspect, whose name was not released, was born in Cardiff, Wales, police said.

The "full circumstances" were still being investigated, Kennedy said, adding that the attack wasn't being investigated as a terror-related. Police were not searching for additional suspects, she said.