Twenty-two people, including children, have been killed and 59 injured in a suspected terror attack at Manchester Arena.

The blast happened at 22:35 BST on Monday at the end of a pop concert by the US singer Ariana Grande.

Greater Manchester Police said the lone male attacker, who died in the blast, was carrying an improvised explosive device which he detonated.

Relatives are using social media to hunt for missing loved ones.

Police have set up an emergency telephone number in response to the attack.

Home Secretary Amber Rudd said it was “a barbaric attack, deliberately targeting some of the most vulnerable”.

Prime Minister, Theresa May, is to chair a meeting of the government’s emergency Cobra committee on Tuesday.

The explosion happened in the arena’s foyer shortly after the concert ended, close to the entrance to Victoria train and tram station.

The station has been closed and all trains cancelled.

The UK threat level has been has been judged to be severe for nearly three years – which means an attack is considered highly likely.

But in recent months the tempo of counter terrorist activity has been increasing with – on average – an arrest every day.

After the attack in Westminster by Khalid Masood in March, police and security officials have been warning that further attacks were almost inevitable.

But they also believed that those were more likely to be low-tech involving knives or vehicles. The fact that the Manchester attack involved explosives will worry them.

Twitter has been flooded with appeals from relatives and friends of missing concertgoers via the hashtag #MissingInManchester.

Facebook also activated a safety check feature so that people can let their family and friends know they are safe.

Greater Manchester Mayor Andy Burnham said the city would “pull together”, adding: “That’s what we are. That’s what we do. They won’t win.”