Police have confirmed there are a number of fatalities following reports of an explosion at the Manchester Arena.
Emergency services are at the venue and Greater Manchester Police said there were “a number of confirmed fatalities and others injured”.
In a message posted on their Twitter account, the force added: “Please avoid the area as first responders work tirelessly at the scene.
“Details of a casualty bureau will follow as soon as possible.”
Witnesses said they heard two loud bangs inside the arena and coming from where the bars are located.
Manchester's Victoria station, which backs onto the arena, has been evacuated and all trains cancelled.
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."
