Pop star Ariana Grande has broken her silence about the horrific bombing that killed at least 22 concert-goers and injured around 60 others after her concert in Manchester, England on Monday night.

The 23-year-old American singer tweeted a message to her followers at nearly 3 a.m. local time, which read: “broken. from the bottom of my heart, i am so so sorry. i don’t have words.”

The star’s manager, Scooter Braun, also tweeted out a message of condolences to the victims of the bombing.

“Words cannot express our sorrow for the victims and families harmed in this senseless attack,” the statement said. “We mourn the lives of children and loved ones taken by this cowardly act.”

A representative for Grande confirmed to multiple media outlets that she was unharmed when a suicide bomber blew himself up in the foyer of the Manchester Arena at around 10:30 p.m. local time just as young fans were leaving the venue after the singer’s performance had finished.

There are unconfirmed reports that the pop star has cancelled the remaining shows of her “Dangerous Woman” tour. Her next concerts were slated for Thursday and Friday at the Q2 Arena in London.

The venue tweeted on Tuesday that they were waiting for further information from the promoters of Grande’s tour on the status of the shows.