19 people have been killed and more than 50 injured following a terrorist attack in Manchester
A witness who was in the arena when the blast went off has told of how he saw concert-goers "running and screaming" after hearing a "loud bang."
Oliver Jones, 17, was at the Ariana Grande concert with his 19-year-old sister.
He said: "The bang echoed around the foyer of the arena and people started to run.”
"I seen people running and screaming towards one direction and then many were turning around to run back the other way.
"Security was running out as well as the fans and concert goers. Reports of blood and people injured."
He added: "You see this on the news all the time and never expect it to happen to you. I just had to run and make sure me and my sister were safe."
Catherine Macfarlane, who was at the gig, told the Reuters news agency: "We were making our way out and when we were right by the door there was a massive explosion and everybody was screaming.
"It was a huge explosion - you could feel it in your chest. It was chaotic. Everybody was running and screaming and just trying to get out of the area."
Majid Khan, 22, said: "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.
"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."
A barman at the nearby Steven Charles Snooker Club, who gave his name as Tyler, said he saw people lying on the ground covered in blood.
"We've had a few people in with panic attacks and in all kinds of disarray."
"There was a gentleman on the floor with his leg all bleeding and woman with blood down one side of her face.
"We felt something but didn't know what it was - there was a sound like thunder."
A woman who said she worked at the arena as staff but did not want to be named said: "All I know is it sounded like a bomb."