Taylor Swift has said she is “completely in shock” after three children were killed and seven people left in a critical condition after an attack in Southport at a dance and yoga class inspired by the US pop megastar. In a post on Instagram, Swift said: “The horror of yesterday’s attack in Southport is washing over me continuously. I’m just completely in shock … The loss of life and innocence, and the horrendous trauma inflicted on everyone who was there, the families and first responders. “These were just little kids at a dance class. I am at a complete loss for how to ever convey my sympathies to these families.” Police said a teenager armed with a knife entered the class at about 11.47am on Monday morning and attacked the children, who were aged between six and 11. Three children, aged nine, seven and six, have died, and eight others were injured, five of them critically. Two adults are also critically injured. Two adults, thought to be the teachers leading the session, were also in a critical condition in hospital, with police saying they “were injured trying to protect the children”. A 17-year-old boy who has been arrested on suspicion of murder and attempted murder is being questioned by police. A number of online fundraisers have been set up for the victims, including one led by Taylor Swift fans “for our little Southport Swifties and families”. Another, which has raised almost £80,000 for the Alder Hey children’s charity, said it hoped to “raise money for the families affected by the tragedy” and “raise funeral funds” for the children who had died. Cristina Jones, who helps run the Taylor Swift UK & EU Facebook group and set up the fundraiser, said they had received donations from across the world. “What compelled us was we were thinking about the fact that these families are going through just unimaginable hell right now,” she told the PA news agency. “I firmly believe there’s nothing we can do to make the families feel better because of what they’re going through right now, but if we’ve taken some sort of burden from them, financial or whatever, it’s nice to know that we’ve done what we can do.” Jones said it was “really lovely” to see Swift share a statement on Instagram paying tribute to the victims, adding: “She’s bringing it to attention and letting the families know she’s well aware and is thinking of them.” Monday’s event was advertised as a Taylor Swift yoga and dance workshop aimed at children aged six to 11, and was reported to be sold out. It also included bracelet making, a popular activity among the singer’s fans, many of whom swap bracelets at her concerts. Swift is on the European leg of her Eras tour and is scheduled to perform in Warsaw, Poland on Thursday, before returning to the UK for a five-night stint at Wembley in mid-August. Alongside Swift, the UK prime minister and King Charles have issued statements expressing their sympathies and offering condolences to the victims. The king said he was “profoundly shocked” by the “utterly horrific incident”, while Keir Starmer said “the whole country is deeply shocked at what they have seen and what they have heard”.