Horrific news broke last night when an explosion rang out at the end of pop singer Ariana Grande‘s concert at Manchester Arena in Manchester, England. According to the most recent report from the Associated Press, the explosion killed 22 people and injured 59. With the nature of the pop concert, many of those effected were teenagers.

A 23-year-old man has been arrested, whom Manchester Police say is in connection to the “apparent suicide bombing,” though the assailant died in the explosion. After the man’s arrest, the Islamic State group confirmed their involvement, saying “a soldier of the caliphate planted bombs in the middle of Crusaders gatherings.”

According to the terrorist group, “30 Crusaders were killed and 70 others were wounded,” but these estimations are significantly higher than police reports.

Prime Minister Theresa May says the threat level remains severe as the investigation continues. “We now know that a single terrorist detonated his improvized explosive device near one of the exits of the venue, deliberately choosing the time and place to cause maximum carnage and to kill and injure indiscriminately,” she said in a statement.

“The explosion coincided with the conclusion of a pop concert which was attended by many young families and groups of children… This attack stands out for its appalling, sickening cowardice, deliberately targeting innocent, defenseless children and young people who should have been enjoying one of the most memorable nights of their lives.”

Mrs. May adds that “it is the worst attack the city has experienced and the worst ever to hit the North of England.” Read her full statement here.

23-year-old pop singer Ariana Grande has remained understandably quiet since Monday night’s events, tweeting only the following message:

Erin McDougle, 20, from Newcastle told The Guardian: “There was a loud bang at the end of the concert. The lights were already on so we knew it wasn’t part of the show. At first we thought it was a bomb. There was a lot of smoke. People started running out. When we got outside the arena there were dozens of police vans and quite a few ambulances.” A group of young men from Sheffield said they had seen at least five people covered in blood and others being carried out by bouncers. “Ariana Grande had just gone behind the curtain and the lights came up when there was this massive bang and a big cloud of smoke. I saw five people with blood all down them.” Sophie Tedd, 25, from Darlington, said the noise and smoke seemed to come from the tiered seating stage right. “We were sitting on that side then suddenly there was this big bang in the block next to us. Everyone started screaming and we nearly got trampled on. There was a burning smell.”

We are incredibly saddened by the events that took place on Monday night, and will continue to share updates as they pertain to the safety of large gathering, live music events. Our hearts go out to Ariana Grande and all those in attendance of her concert, and to those effected by this madness.

[Photograph by Christopher Furlong / Getty Images]