Pop star Ariana Grande has canceled her "Dangerous Woman" tour in the wake of a terror attack following her concert in Manchester that left 22 people dead, a source with knowledge of the situation told CNN.

The decision came less than a week after the explosion at the concert, which occurred after Grande had finished performing. 22 people were killed and 59 injured, including children.

ISIS has claimed responsibility.

Grande expressed her sorrow in the hours following the incident.

"Broken," the singer tweeted. "From the bottom of my heart, i am so so sorry. i don't have words."

Grande was physically unharmed, a source close to the situation told CNN.

Grande's management put out a lengthier statement, saying "words can not express our sorrow for the victims and families harmed in this senseless attack."

The Manchester concert was to be the first of three concerts in the UK.

Her next concert was set to take place on May 25 at the O2 Arena in London.

Other dates included shows in Belgium, Poland, Germany and Switzerland.