Latest: Terror threat level increased from severe to critical indicating further attack is 'imminent'

Latest: Britain was braced for further terrorist attacks following the Manchester atrocity as Theresa May said the threat level was being raised to its highest possible rating.

• Police have said an explosion at an Ariana Grande concert in the Manchester Arena at around 10.35pm last night was a terror attack.
• 22 people, including many children, were killed and 59 people, including 12 under the age of 16, were taken to hospital after the blast. An additional 60 people were treated at the scene.
• The attack was carried out by suicide bomber Salman Abedi, 22, who detonated an improvised explosive device. He died at the arena.
• Security services are investigating whether he acted alone or was part of a network.
• A 23-year-old has been arrested in South Manchester in connection with the incident.
• Islamic State has claimed responsibility for the attack.
• The first three victims to be named are Georgina Callander, Saffie Roussos and John Atkinson.
• A vigil has been held this evening in Albert Square, Manchester.
• Extra police officers have been put on duty in London in the wake of the attack.
• A controlled explosion was carried out this afternoon to gain access to Abedi's address in Fallowfield, Manchester.