“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,” a concert-goer told The Guardian.
“I saw five people with blood all down them,” said another fan.
One concertgoer, 22-year-old Majid Khan, told The Independent: “I and my sister, along with a lot of others were seeing Ariana Grande perform at Manchester Arena, and we were all exiting the venue when around 10.40-10,45pm-ish, a huge bomb-like bang went off that hugely panicked everyone and we were all trying to flee the arena.
“It was one bang and essentially everyone from the other side of the arena where the bang was heard from suddenly came running towards us as they were trying to exit Trinity Way and that was blocked so everyone was just running to any exit they could find as quickly as they could.
“Everyone was in a huge state of panic, calling each other as some had gone to the toilet whilst this had gone off, so it was just extremely disturbing for everyone there.”
Emergency services are currently investigating the incident.