Ariana Grande has called off two London concerts and five in Europe after a suicide bomber killed 22 people at her performance in Manchester, England, the U.S. pop singer's representatives said on Wednesday.

Monday's bombing, which killed 22 people and wounded 64, also resulted in the cancellation of next week's London premiere of the superhero film "Wonder Woman" and increased security for a music festival this weekend featuring pop star Katy Perry in the northern English city of Hull.

Grande, 23, who tweeted earlier this week that she was "broken" by the Manchester attack, had been due to perform on Thursday and Friday at London's O2 arena as part of her "Dangerous Woman" tour.