In pictures: Manchester attack aftermath
- Published
The blast happened at 22:33 BST on Monday at the end of a concert by the US singer Ariana Grande.
The explosion happened in the foyer of the 21,000-capacity venue, shortly after Ariana Grande left the stage.
Casualties were helped at the scene and the wounded are now being treated at six hospitals around the city.
Concertgoers consoled each other after the explosion.
Relatives are using social media to hunt for missing loved ones.
The emergency services have been praised for their response. Armed police were called to the incident and more than 60 ambulances were sent to the scene.
Many of the injured people received treatment at the scene.
Victoria rail station, which is next to the arena, was closed after the explosion
Police have set up an emergency telephone number in response to the attack. It is: 0161 856 9400.
Armed officers patrolled outside the venue after the blast, which police are treating as a terror attack.
The concert was part of Ariana Grande's world tour and was reported to have been a sell-out.
Police put the surrounding area into lockdown after the explosion, which also meant many concert-goers were unable to return to their vehicles in car parks.
Prime Minister Theresa May described it as an "appalling" attack.