On 22 May , twenty-two people were killed when a suicide bomber detonated a homemade device laden with shrapnel in the lobby of the Manchester Arena at the end of an music concert with American singer Ariana Grande . Two-hundred people were injured in the attack , the worst on British soil since the 7 July 2005 London bombings . After a COBRA meeting with Greater Manchester Police ( GMP ) 's Chief Constable Ian Hopkins on 23 May , May announced that the UK 's terror threat level had been raised to " critical " , and remained so until 27 May , when it was reduced to its previous level of severe . Within hours of the attack , information given confidentially to security services in the United States and France were leaked to the news media , leading to condemnation from Home Secretary Amber Rudd . On 25 May , GMP said it had stopped sharing information on the attack with the US intelligence services . May said she would make clear to US president Donald Trump that " intelligence that has been shared must be made secure . " Trump described the leaks to the news media as " deeply troubling " , and pledged to carry out a full investigation . May created the Commission for Countering Extremism in the aftermath of the bombing
were killed
Manchester Arena bombing
Premiership of Theresa May