Celebrities are taking to Twitter to express their condolences and concern following a suicide bombing at an Ariana Grande concert at Manchester Arena on Monday (22 May) night in which at least 22 people were killed, including children.

Grande's representative told NBC Nightly News that the pop star "is OK. We are further investigating what happened". The Side To Side singer's entourage was also safe, the main support act Bia confirmed.

Hours after the explosion, the 23-year-old pop star finally spoke out on Twitter: "broken. from the bottom of my heart, i am so so sorry. i don't have words".

TMZ reported she was "in hysterics" after learning of the deaths and injuries of her fans. Grande's next concert, scheduled for Thursday (25 May) in London's O2, is "up in the air," TMZ noted.

Footage shared on Twitter shows frightened concert goers scrambling to leave Manchester Arena as panic ensued. Police confirmed that at least 22 people were killed and dozens more were injured.

Authorities in Manchester said the blast is "being treated as a terrorist incident". No terrorist organisation had initially taken responsibility for the attack.

Celebrities from both sides of the pond have taken to Twitter to share their support for those affected.