A lone suspect detonated a homemade bomb at the conclusion of a sold-out concert by Ariana Grande in Manchester, in the north of England, killing 22 people and injuring almost 60 others, including several children.

The Islamic State, (aka ISIS/ISIL) claimed responsibility for the attack overnight, posting on social media, “One of the soldiers of the Caliphate was able to place an explosive device within a gathering of the Crusaders in the city of Manchester.”

“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,” said Chief Superintendent Ian Hopkins of Manchester Police. This most recent attack is the deadliest in the United Kingdom since the 2005 London bombings that killed 55 people. Police believe they know the identity of the attacker, but can not release it at this stage.

The attack happened as concertgoers were leaving Manchester Arena as Grande had just wrapped up her performance. A suicide bomber died after detonating a homemade explosive in the lobby area between the 21,000 seat arena and the next-door Victoria station. The ensuing explosion sent nuts and bolts tearing through the crowd as mostly youngsters and teenagers were leaving the venue and parents were waiting to collect their children. Grande herself was not injured in the attack.

Calvin Welsford, an 18-year-old at the concert, claims that the mayhem began only minutes after Grande left the stage when he heard a “loud bang”. “Ariana was off the stage, she’d finished her set,” he said. “I looked around because I heard this big bang, people screaming and crying and flooded towards the stage.” Home Secretary Amber Rudd said in a statement, “This particular attack was aimed at the most vulnerable in our society, young people, children at a concert,” but adding that Britons should “remain alert, not alarmed.”

Six hospitals across the city are struggling to cope with the wounded, several currently unable to admit anyone not deemed as an emergency case. Eyewitness Jane Hanson, 44, who was watching the concert from a box with her 16-year-old daughter tried her best to put the situation into words. “I saw children hysterically crying and panicking. One man was carrying children in his arms,” she said. “One girl ran outside the venue and was shouting ‘We don’t know where my sister is’. Children were just running for their lives. It was blood-curdling.”

ISIS claimed responsibility for the attack in a statement posted to the group’s Telegram channel, claiming that a “soldier of the caliphate” was able to “plant explosive devices” at the Manchester Arena, although the claim doesn’t include any pictures or details. Also, an unverified Twitter account posted tweets showing the ISIS black flag alongside the hashtags #IslamicState and #Manchesterarena, as well as the message “You forget our threat? This is the just terror.” It is still unclear of the exact significance, if any, of the tweets, but the account has since been deleted.

While Donald Trump referred to the attackers as “Evil losers” in a speech this morning, British Prime Minister Theresa May recently gave a statement commending the efforts of the 400 police officers deployed during the night, as well as paramedics, doctors and nurses, who have worked continuously in the wake of the tragedy. Although May had previously called an early general election for the UK for June 8, all campaigning has now been suspended indefinitely.