A suicide bomber has killed 22 people - including children - in an explosion that tore through fans leaving an Ariana Grand pop concert in Manchester, according to the Telegraph.

At least 59 people were also injured when the blast caused by an improvised explosive device carried by the attacker detonated at the Manchester Arena after the performance on Monday night.

Victims described being thrown by the blast, which scattered nuts and bolts across the floor and told of seeing smoke and smelling burning in the foyer area.

It is the worst terror attack to hit Britain since the July 2005 suicide bomb attacks in central London in which 52 people were killed and came four years to the day Lee Rigby was murdered by Islamist extremists.

Police were called to reports of an explosion at 10.33pm, shortly after Grande, the US singer, had finished her performance as thousands of people streamed out of the Arena.

More than 240 calls were made to the emergency services, with responders including 60 ambulances flooding the area and more than 400 police officers deployed as part of the operation.

Announcing that the death toll had risen, Greater Manchester Police chief constable Ian Hopkins said: "What I can confirm is that there are children among the deceased."

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.

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.

Police have appealed for concert-goers and witnesses to provide police with footage from the scene if they believe it can assist the probe.