Twenty-two people including some children have been killed in a suicide attack carried out by one man after a Ariana Grande concert in Manchester.
"We believe, at this stage, the attack last night was conducted by one man," Manchester Chief Constable Ian Hopkins said.
"The priority is to establish whether he was acting alone or as part of a network.
"The attacker, I can confirm, died at the arena. We believe the attacker was carrying an improvised explosive device which he detonated causing this atrocity."
