22 people have been killed and 59+ injured after explosions were heard inside Manchester Arena at the end of an Ariana Grande gig tonight.
Video footage showed people fleeing in tears from the venue after bangs rang out immediately after the concert finished.
Bloodied concertgoers were pictured being helped by emergency services outside the gig and armed police were seen patrolling the arena.
Evie Brewster, who attended the concert, told MailOnline: 'Ariana Grange had just finished her last song and left the stage when a huge explosion sounded.
'Suddenly everybody started screaming and running for the exit.
'We could hear the police and ambulance sirens. It was terrifying.
'There were thousands of people trying to get out at once. They were all screaming and crying. The whole place smelt smokey and burnt.
'The explosion sounded like it was inside the building somewhere.'
Manchester's Victoria station, which backs onto the arena, has been evacuated and all trains cancelled.
Greater Manchester Police said: 'Emergency services are currently responding to reports of an explosion at Manchester Arena.
'There are a number of confirmed fatalities and others injured.
'Please AVOID the area as first responders work tirelessly at the scene. Details of a casualty bureau will follow as soon as available.'
Catherine Macfarlane told Reuters: '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 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.'
Another concert-goer Laura, 22, told MailOnline: 'There was a woman leaning against a car in the car park with her head down, covered in blood and a little girl being lifted away by paramedics. There were quite a few people injured in the car park.'
Her friend, Livvy, 22, added: 'we saw the explosion happen. Bits of it hit me. My first thought was, 'that's a bomb'.
'It was just when we were leaving. We saw a flash of light and smoke.
'We're really shaken up. If we had been there moment earlier we would have been caught up in it rather than seeing it.'
Oliver Jones, 17, was at the concert with his 19-year-old sister.
He said: 'I was in the toilet and heard a loud bang just after the concert had finished and people had started to leave.
'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: 'In so much shock and panic. 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.'
Suzy Mitchell, 26, whose flat is opposite the venue, reported a huge bang rocking the neighbourhood.
She told the Press Association: '(I) just heard a huge bang from my bed, came out to the front of my apartments (we're on the top floor so have perfect view) and everyone was running away in big crowds.
'The bang was so big I heard it from my room which is at the back of the apartment blocks.
'Currently lots of emergency services going to and from. But can't see anything substantial as of yet except fleeing people and lots of cars.
Former Manchester United footballer Rio Ferdinand said: 'Just heard the news what's happening in Manchester... hope everyone is safe and sound!'
A spokesman for Greater Manchester Police said: 'Emergency services responding to serious incident at Manchester Arena. Avoid the area. More details will follow as soon as available.'
A British Transport Police spokesman said: 'We are aware of an incident at Manchester Arena. We have officers at the scene and will provide further updates as soon as possible.'