It was shortly before midday on what felt like the hottest day of the year when the sound of children playing was shattered by screams. Girls as young as five ran in fear, some covered in blood, after their Taylor Swift dance class on the first week of the summer holidays turned into an atrocity. A 17-year-old boy wearing a hood and a Covid face mask had walked into the class in the seaside town of Southport, having taken a taxi from a nearby village. Alaina Riley, 18, said her aunt rang her “screaming down the phone” after witnessing “little kids run out screaming covered in blood” and two staff members “crawling” out of the building. Parents had just arrived to pick up their daughters from the Hart Space, which was hosting the Swift-themed holiday club, when the attack began. Colin Parry, the owner of nearby Masters car repair shop, said he had a brief exchange with a male he believed to be the attacker minutes before the stabbing began. He told the Guardian: “He came down our driveway in a taxi and didn’t pay for the taxi, so I confronted him at that point. He was quite aggressive he said: ‘What are you gonna do about it?’ “The customer I was dealing with at the time confronted him as well, and he [the attacker] said the same to him. Then he turned around and walked out of the drive.” Parry said he continued working on a vehicle when moments later he got a telephone call from a colleague saying: “You need to get outside here now, get out here.” “I went out and there’s two or three kids just lying on the floor. I mean, it’s a frenzied attack. It’s not one stab. He’s gone crazy, the lad’s gone crazy.” Parry said his colleague ran to the door of the dance studio after he heard “screaming that wasn’t normal”. “He went out to see what it was and about 10 kids go running past him, all bleeding, and one of them collapsed on the floor outside the neighbour next door but one and he was attending to her.” Parry said the children involved were primary school age and that one older girl, believed to be a teenager, had been stabbed as she tried to usher the youngsters to safety out of the building. He said: “He just stabbed her in the back as well while she was trying to get the other kids back. “I don’t know how many were in the building after that but I know probably three or four came out afterwards being carried out and put on the floor for people to work on.” Parry said he rang 999 and told them: “You need to get ambulances here now. We need police. We need armed police. There’s a kid dying here on the floor.” Locals were bringing children out of the building trying to tend to their injuries before the emergency services arrived. Parry said: “When he [the attacker] came in here you wouldn’t have known that he had anything on him or any intent to do anything like that, but that’s probably why he didn’t carry on the confrontation with us – because he knew what he was going to do.” He said he was “numb” after witnessing the atrocity. “It was horrific, absolutely.” Neighbours said they were first alerted to the incident at about noon when they heard a woman in the street, shouting for help. Further down the road, Debrah Parker, 57, said she heard a young girl come out of the building saying: “Mum, I’ve been stabbed, I’ve been stabbed.” “She [the mother] bundled her in the car as fast as she could, she was screaming: ‘Help me, help me.’ She was covered in blood.” “I heard her shouting: ‘My daughter has been stabbed,’ begging for help. She was trying to flag down the police,” Michelle Birkby, 36, said. They said the woman had carried her daughter away from the scene, but another neighbour had got into the car with the woman, to help her drive her daughter to where paramedics were inside the cordon. “She was desperate for help,” Birkby added. Soon after, she said, large numbers of police arrived on the scene. “It seems a bit insane to me, I can’t fathom,” she added. “We’re just all in a bit of shock.” Witnesses said police and paramedics were treating the children in the middle of the street before rushing them to hospitals across Merseyside. One resident said police officers placed injured girls in the back of their patrol car, while parents who had turned up to collect their daughters were instead trying to resuscitate them in the street. One parent, who did not wish to be named, said his daughter was “traumatised” by the attack. He said: “My daughter was in it and she was traumatised. She ran away and she’s safe.” Local WhatsApp groups were filled with messages saying: “Lock your windows, lock your doors” over fears a knifeman was running around stabbing people. One nearby resident said she ran down her street telling neighbours to lock their doors and stay inside. Ashen-faced paramedics and firefighters sat with their heads in their hands outside the police cordon, some being comforted by residents, after the casualties were taken away. “They looked white-washed. Shocked. Parents as well,” said Cheryl Grisedale, 56, an upholsterer whose semi-detached Victorian house looks on to Hart Street. She had taken multipacks of water, soft drinks and crisps to the officers standing in baking heat guarding the aftermath of the attack. A retired teacher, whose house backs on to Hart Street, said she heard the blare of sirens as she prepared to leave her property shortly after midday. “It’s just appalling,” she said. “I won’t say the old cliche of ‘it doesn’t happen around here’ because these days anything can happen but I’m just shaken that this could happen in this little quiet suburban area.” Later in the day, a 17-year-old boy from Banks, a village 5 miles from the scene, was arrested in connection to the stabbings and was taken into police custody. Police closed off a close of neat modern houses in Banks. It is understood that the suspect took a taxi from here directly to the scene. Several police cars and officers remained stationed on the street throughout the afternoon and into the evening, with a helicopter flying overhead. But neighbours said that although this was a small community, the first anyone knew of what had happened was when police vans turned up. “I know it’s a small village but we don’t know anything about it,” one said. “We’re just absolutely shocked down here,” another said. “It’s a small village but we don’t know who’s moving in.”