Taylor Swift says she is 'in shock' after 3 children died in an attack on a U.K. dance class

British police say a third child has died after a stabbing at a kids' yoga and dance class.

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A 9-year old girl wounded in a stabbing attack at a Taylor Swift-themed dance and yoga class in northwestern England died Tuesday, bringing the death toll to three, as police questioned a 17-year-old suspect arrested minutes after the rampage.

Merseyside Police said the other fatalities were girls aged 6 and 7.

Eight children and two adults remain hospitalized after the attack in Southport. Both adults and five of the children are in critical condition.

Swift said she was "completely in shock" and still taking in "the horror" of the event.

"These were just little kids at a dance class," she wrote on Instagram. "I am at a complete loss for how to ever convey my sympathies to these families."

A 17-year-old boy was arrested on suspicion of murder and attempted murder.