Twenty-two people, including children, have been killed and 59 injured in a suicide attack at Manchester Arena.
Announcing that the death toll had risen and that children are among the dead, Greater Manchester Police chief constable Ian Hopkins said: “This has been the most horrific incident we have had to face in Greater Manchester and one that we all hoped we would never see.
The blast happened in the foyer at 22:35 BST on Monday at the end of a concert by US singer Ariana Grande.
Police said the lone male attacker, who died in the blast, detonated an improvised explosive device.
The General Election campaign has been suspended in the wake of the terror attack and Prime Minister Theresa May is chairing an an emergency Cobra meeting at 9am.
Eyewitnesses described seeing metal nuts and bolts among the debris, and spoke about the fear and confusion that gripped the concert-goers.
Andy Holey, who had gone to the arena to pick up his wife and daughter, said: “An explosion went off and it threw me about 30ft from one set of doors to the other set of doors.
“When I got up I saw bodies lying on the ground. My first thought was to go into the arena to try to find my family.”
A large cordon remains in place around the arena and nearby Manchester Victoria Station, which was evacuated during the incident and remains closed, while forensic investigators gather evidence.