Updated 12.14pm: Manchester Police have confirmed 19 people have died following reports of "explosions" and panic at the Manchester Arena in the UK, where Ariana Grande was performing.
Manchester Police also confirmed 50 people have been injured at the event being treated as a "terrorist incident", and are warning people to avoid the area as emergency services run to the scene.
"Just got out of Manchester arena after seeing Ariana perform. There was a loud bang when the lights came on & everyone ran out screaming," one person wrote on Twitter.
Concertgoer Hannah Dane told the Guardian there was "quite a loud explosion heard from inside the Manchester arena and it shook, then everyone screamed and tried to get out".
"As we got outside, lots of police came racing towards the area and the whole of the Victoria train station was surrounded by police."
There were people "screaming and crying everywhere shouting that there's a bomb and also people were saying there's a shooter," she said.
Manchester Arena said the incident took place “outside the venue in a public space” with one explosion reported to have hit the foyer of the building at about 10:30pm, British Transport police said.
Ariana Grande's label representative has told Variety the popstar is "okay" after the incident was reported on social media.