Manchester 'explosion' being treated as 'possible terrorist incident'

Counter-terrorism experts gathering in London on Tuesday following blast that left at least 19 people dead and 50 others injured

Police are treating the explosion in Manchester as a suspected terrorist incident (Getty Images)

Police are treating an explosion in Manchester that killed 19 people as a terrorist incident.

Greater Manchester Police confirmed the blast was "currently being treated as a terrorist incident" and said they were working with national police agencies and the intelligence services to investigate the blast.

Senior counter-terrorism officers are understood to be gathering in London following the explosion, which occurred at the Manchester Arena at 10.33pm, at the end of a concert by pop star Ariana Grande.

Police also carried out a controlled explosion nearby following reports of a suspect device that later turned out to be a bag of clothes.

The explosion is said to have gone off just outside the entrance to the venue as thousands of people were leaving.

If confirmed as a terrorist attack it would the worst atrocity in the UK since 56 people were killed in the 7/7 London bombings in 2005.