A blast struck a music concert by American pop star Ariana Grande in Manchester, killing 22 people and wounding more than 50 others on Monday (22 May) night. The incident took place at 10.35pm BST outside the Manchester Arena. British Prime Minister Theresa May said the incident was being treated as an appalling terrorist attack. Unconfirmed reports from two US security sources suggest a suicide bomber was responsible for the attack, but there is no official confirmation from the UK police.