Singer Liam Payne has cancelled his forthcoming tour after suffering a serious kidney infection.
The One Direction star has pulled out of performances in South America after being taken to hospital.
The 29-year-old said that he was following doctor's orders and planning to "rest and recover" following his scare.
He apologised to fans who had bought tickets and said he hoped to reschedule the live dates.
In a statement posted on Instagram on Friday, Payne said: "It's with a heavy heart I have to tell you that we have no other choice but to postpone my upcoming tour of South America.
"Over the past week, I've been in hospital with a serious kidney infection, it's something I wouldn't wish on anyone, and doctor's orders are that I now need to rest and recover."
He continued: "I was beyond excited to come play for you guys. To all of you who have bought tickets: I'm so sorry."
Fans who had bought tickets would be refunded, Payne said, adding that he was "working to reschedule the tour".
"Please look out for updates from your point of purchase," he said. "Thanks as always for the love and support, and look forward to seeing you soon."
In an accompanying video addressing fans, Payne told fans: "This really is the last news I want to be telling you... We started rehearsals and I've been advised that now is really not the right time to be travelling on the road while I recover from this.
"I've got the best people around me at home trying to help me recover as we speak."
Payne joined One Direction in 2010, when he was put together with Harry Styles, Niall Horan, Zayn Malik and Louis Tomlinson on ITV talent competition the X Factor.
The group went on to score hits with Best Song Ever, What Makes You Beautiful, Kiss You, Steal My Girl and Live While We're Young.
After going on hiatus in 2015, Payne launched a solo career and enjoyed chart success with Strip That Down, Get Low, Familiar (featuring J Balvin) and For You (with Rita Ora).
Payne had been due to play dates in Peru, Chile, Brazil, Argentina, Mexico and Colombia on the tour.