Numerous witnesses have described the scene before and after the deadly Manchester Arena explosion, which is being treated as a possible terrorist incident.

At least 22 people were killed and 59 others taken to hospital with various injuries after the Ariana Grande concert.

Gary Walker, who along with his wife was injured as they waited in the foyer to collect their children, told the BBC he saw what he thought was makeshift shrapnel from an explosive device:

“[There was] a massive flash, and then a bang, smoke, a pain in my foot, my leg,” he said.

“I turned around to my wife who was beside me. She said, ‘I need to lay down’. I laid her down on floor. She’s got a stomach wound and possibly a broken leg.

“There’s glass and there’s nuts — metal nuts that’ve been packed in the device that’s exploded — because I can’t think of anything else that’s got nuts that’d be flying around.”

Many of the concert-goers were young girls. Photo: Getty

Sisters Sophie and Abigail became separated from their parents, who were injured in the incident.

The sisters told BBC Radio in Manchester they heard a massive bang and the floor of the arena shook before people began to run for the door.

Sophie said she held on tight to her sister as they frantically navigated their way to an exit and out of the arena.

“We were just about to leave the exit door, and someone asked the security what had happened and the security said it was just a balloon that must have gone off, but then when we started going down the stairs, there was police everywhere, and we didn’t know what was happening,” she said.

The sisters managed to call their parents.

“Yeah, we got hold of my dad and he said they had been injured and we were inside and tried to find them but we weren’t allowed in so we kept telling them where we were each time we had to move,” Sophie said.

Victorian Sarah Stoffles was working in a nearby cafe when she heard the blast and saw people rushing out of the arena in a panic:

“We had a few people from the concert actually come into the [cafe], where I work. They were all a bit flustered and we had to try and calm them down,” she said.

“They were all 17-year-old girls actually, so they were a bit traumatised, saying they saw people with blood all over them.”

Police and fans close to the Manchester Arena. Photo: Getty

Andy Holey, who was waiting at the arena’s doors for his wife and daughter who had been at the concert, described the moment of the explosion to the BBC:

“I was waiting up at the first set of white doors. As I was waiting an explosion went off and it threw me through the first set of doors about 30 foot to the next set of doors.

“When I got up and looked around there was about 30 people scattered everywhere, some of them looked dead, they might have been unconscious but there was a lot of fatalities.

“My first thing was to run in the stadium to try and find my wife and daughter.

“When I couldn’t find them I looked back outside and the police, fire and ambulance were there and I looked at some of the bodies trying to find my family.

“Luckily they weren’t there, I managed to find them outside the arena and got them back to the hotel.”

Parents collect their daughter who was given refuge at a hotel near the venue. Photo: Getty

British man Adam Murphy was also at the scene. He told triple j’s Hack he believes there was an explosion underneath the stands where he was sitting.

“Without exaggerating, the concert had finished about one second before, the lights had literally just come on. [The explosion] shook the room that we were in.”

“Everyone started screaming. I’ve never run so fast in my life.”

“There was a woman that couldn’t find her little girl, she was crying. I saw another man covered in blood, there were people laid on the floor.”

“It smelt like the entire place was on fire. I’ve never smelt anything like it, even outside, all you could smell was burning.

“It was all bit of a blur really, no one really knew how to respond to it,” he said, after he and his friends returned home safely.

Joe Gregory, a 22-year-old who was waiting for his girlfriend outside in his car, captured the moment of the explosion with a dashboard camera.

“Never felt so scared in my life,” he first wrote on Twitter.

“I was waiting to pick my girlfriend and her sister up from the concert.

https://twitter.com/JoeAaronGregory/status/866784565821677569

– ABC