Demi Lovato has cancelled her Sunday night show in London – hours before she was due to take to the stage.
The US singer had been due to perform at the O2 arena at about 21:00 BST, but posted a message on Twitter at 17:17 BST postponing the event. Doors had been due to open at 18:00 BST.
Blaming swollen vocal cords, the star said she was “very, very sick” and added: “It breaks my heart to let you down.”
The concert has been moved to 25 June.
Lovato said she feared performing on Sunday could injure her vocal chords and lead to the rest of her tour being cancelled. She said she had been examined by an ear, nose and throat doctor.
The Heart Attack singer is due to perform four other UK shows in the coming week – in Birmingham, Glasgow, Newcastle upon Tyne and Manchester.
She did not mention those shows in her cancellation message.
In the message, the singer said: “I’m so so so sorry to disappoint any of my fans in London that have travelled hours to be here by plane or car, and to all of the fans that got these tickets for their birthday, holiday or any other special occasion.
“It breaks my heart to let you down. Just know I feel your frustration and I wouldn’t do his unless I absolutely had to.”
A statement from concert producer Live Nation confirmed the postponement.
“The show will now take place on Monday June 25th,” the company said.
“All tickets will remain valid for the new date. Please contact your point of purchase for all ticket inquiries.”
Fans of the singer responded with messages of support.