Manchester // A suicide bomber killed 22 people in an attack targeting young fans at a pop concert by US star Ariana Grande in Manchester. The explosion sparked panic as Grande’s audience of mostly young teenagers fled the 21,000-capacity venue after an explosion in the foyer area at the end of the concert. A number of children were among those killed and 59 people were injured in Britain’s worst terrorist attack since the London bombings of July 2005. The first victim to be named was 18-year-old Georgina Callander, after her school, the Runshaw College Sixth Form Center in Lancashire, confirmed the news on its Facebook Page. Eight-year-old Saffie Rose Roussos from Leyland, near Preston, was also among the dead, said Lancashire County Council in north-west England on Tuesday. As with previous attacks, ISIL swiftly claimed that one of its militants had carried out the attack. Greater Manchester Police chief Ian Hopkins said the attacker had set off an “improvised explosive device” as the audience was leaving the concert. “The priority is to establish whether he was acting alone or as part of a network,” Chief Constable Hopkins said. “The attacker, I can confirm, died at the arena. We believe the attacker was carrying an improvised explosive device which he detonated causing this atrocity.” British police on Tuesday arrested a 23-year-old man in connection with the terror attack. “With regards to the ongoing investigation into last night’s horrific attack at the Manchester Arena, we can confirm we have arrested a 23-year-old man in South Manchester,” police said. British prime minister Theresa May said it is “beyond doubt” that Britain and the city of Manchester have fallen victim to “a callous terrorist attack”. Speaking outside her offices in London, she said that “although it is not the first time Manchester has suffered in this way, it is the worst attack the city has experienced, and the worst ever to hit the north of England”. Mrs May said police believe they know the attacker’s name but were not disclosing it immediately. Dozens of ambulances and bomb disposal teams rushed to the venue at 10.30pm UK time (1.30am UAE time), as worried family members searched for their loved ones and residents opened their doors to stranded concertgoers after trains were cancelled. At least two parents waiting for their children outside were injured by the explosion, with one saying he had been hit by shrapnel in his leg and another feeling “heat on my neck”. Jenny Brewster said she was leaving the concert with her 11-year-old daughter when the blast hit. “As I turned around, boom, one loud noise,” she told Sky News. “A gentleman said ‘run!’ so we ran.” Outside, she said, “you could smell the burning.” Home secretary Amber Rudd described the attack as “barbaric” and “deliberately targeting some of the most vulnerable in our society – young people, children out at a pop concert”. Grande, who was due to give a concert in London later on Tuesday, said she was “broken” in a tweet. “Broken. From the bottom of my heart, I am so so sorry. I don’t have words,” she wrote. One witness said Grande had just finished her final song and said “Thank you, Manchester,” before leaving the stage. The foyer of Manchester Arena connects the auditorium with Victoria train and tram station, a major transport hub on the northern edge of the city centre. Gary Walker from Leeds told BBC Radio 5 Live he was hit by shrapnel in his foot and his wife sustained a stomach wound as they waited for their daughters. “We heard the last song go and then suddenly there was a massive flash and then a bang and smoke,” he said. Isabel Hodgins, an actress who had been attending the concert, told Sky News: “Everybody was panicking, there was pushing up the stairs. “The corridor was full, it smelled of burning, there was quite a lot of smoke as we were leaving. “It’s just shocking and we just feel very shaken up. We’re just lucky to have gotten away safely,” she said. Majid Khan, 22, who was attending the concert with his sister, said: “A huge bomb-like bang went off that hugely panicked everyone and we were all trying to flee the arena”. Calvin Welsford, 18, from Bristol told the BBC: “It almost sounded like a gunshot”. “I looked around and people were just spilling down, heading out of the building”. “I was actually having an asthma attack. It was sheer panic,” he said. Britain’s terrorist threat level stands at “severe”, the second-highest rung on a five-point scale, meaning an attack is highly likely. The US Department of Homeland Security, Britain’s biggest intelligence partner, said it was closely monitoring the situation. “We are working with our foreign counterparts to obtain additional information about the cause of the reported explosion as well as the extent of injuries and fatalities,” the department said. Tributes poured in for Manchester from around the world including from London mayor Sadiq Khan, whose city was struck by a terror attack just two months ago. “Our thoughts are with all those killed and injured tonight and our brave emergency services,” he said. The pop world also rallied with Katy Perry tweeting: “Praying for everyone at Ariana Grande’s show”. US pop princess Taylor Swift, a friend of Grande, wrote: “My thoughts, prayers and tears for all those affected by the Manchester tragedy tonight”. In Manchester, residents tweeted with the hashtag #RoomforManchester to offer a place to stay and there were reports of taxis taking passengers for free. Concerned relatives used the hashtag #MissinginManchester to locate loved ones. Train services to and from Manchester Victoria Station — located under the Arena — had been cancelled. “Disruption is expected to continue until the end of the day,” National Rail said in a statement. A few hours after the blast, police carried out a controlled explosion in a small park near the venue a but said the item turned out to be only abandoned clothes. *Agence France-Presse, Associated Press and Reuters