Police said 22 people were killed and approximately 59 others were injured in an explosion at Manchester Arena in the U.K. on Monday night, where Ariana Grande was performing a concert, PEOPLE confirms.
Chief Constable Ian Hopkins said the explosion occurred around 10:33 p.m. local time near the ticket office outside the arena. The attack was carried out by a lone suspect carrying a bomb, 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,” Hopkins said.
He added, “We have been treating this as a terrorist incident and we believe, at this stage, the attack last night was conducted by one man. The priority is to establish whether he was acting alone or as part of a network.”
Law enforcement officials in the U.K. suspect the bombing was the work of a suicide bomber, according to various reports. CBS News is reporting that the alleged bomber traveled to the arena via train and detonated the bomb as people were leaving.
The victims’ identities were not confirmed by authorities, though numerous reports highlighted Grande’s largely youth-skewing fan base, including children, teens and young adults.
British Prime Minister Teresa May says her thoughts are with victims and families after what is being treated by police “as an appalling terrorist attack.”
Local investigators and arena authorities could not immediately be reached for further comment.
“Ariana is okay,” her rep said in a statement to PEOPLE. “We are further investigating what happened.”
“I was waiting for the kids to come out. We heard the last song, and quite a few people were flooding out and then suddenly there was a massive flash and then a bang [and] smoke,” witness Gary Walker told BBC Radio.
The explosion was by the foyer door, near a merchandise table, he said.
Echoing other witness statements, Josh Elliot told the BBC that the explosion was heard just as Grande finished her final song of the night.
Eyewitness Andy Holy spoke to the BBC and said he was blown through a door at the arena.
He added, “Whoever has done it, has done it on a kids concert.”
“My ears are still ringing,” he said. “The whole building shook.”
Esme Findlay was inside the arena at the time and tells PEOPLE, “Everyone was laughing and talking about the show before the sound. [Then] everyone began screaming immediately and pushing to get out.”
“It was very loud afterwards because of the screaming,” she says. “No one knew if it was a bomb or what it was, but people were screaming ‘bomb, bomb,’ and there was a lot of panic.”
“Outside, people were screaming names of people,” says Findlay, 20. “I think they were people who they had been with and couldn’t find.
“Everyone was looking for someone. I saw some girls crying and a woman was asking them where their parents were. It was the scariest thing I’ve ever seen in my life.”
Holy, who said he was there with his wife and daughter, told the BBC he saw at least 30 casualties, including many children.
Many of those hurt or killed appeared to be waiting outside the arena to meet their kids, said Holy, who is safe with his family at their hotel.
Police quickly confirmed that a “suspicious item” found near the arena was actually clothing.
Sam Coley lives about half a mile from the arena and tells PEOPLE even he could hear the sounds of a “massive bang.”
“There was an unbelievable amount of police cars and ambulances and people on the street,” says Coley, 24. “Around 50 police vehicles must have gone past my flat, if not more. Then the ambulances started coming in a convoy.”
“It was a loud bang,” he says, “Loud enough to hear over the TV inside my flat — and I’ve got pretty thick doors and double glazing.”
One video shared on Twitter appeared to show the inside of the arena in the aftermath of the incident, with people screaming and streaming to the exits.
Social media users soon began circulating the hashtag #RoomForManchester to alert stranded people to places where they could stay for the night.
A local hotel reported taking in more than 50 youths, some of whom were waiting to be reunited with parents and guardians.
This is a breaking news story. Please return for updates.
• With reporting by J.D. HEYMAN, JEFF NELSON and SIMON PERRY