Former One Direction star Liam Payne says he's been forced to cancel gigs after spending time in hospital with a "serious kidney infection".
The 29-year-old singer said he had "no choice" but to postpone his upcoming tour of South America "with a heavy heart".
"Over the past week I've been in hospital with a serious kidney infection," Payne posted on Instagram.
"It's something I wouldn't wish on anyone, and doctors' orders are that I now need to rest and recover."
He added: "I was beyond excited to come play for you guys.
"To all of you who have bought tickets: I'm so sorry. We're working to re-schedule the tour as soon as we possibly can, but for now we will be refunding the tickets - so please look out for updates from your point of purchase.
"Thanks as always for the love and support, and look forward to seeing you soon."
In an accompanying video, Payne said he had begun rehearsing for the tour but been told that "now was really not the right time to be out on the road".
Once he has recovered he will return with an "even bigger, better show", he vowed.
Payne embarked on a solo career after One Direction announced they were going on an indefinite hiatus in 2015.
He was part of the original line-up, formed in 2010, alongside Zayn Malik, Louis Tomlinson, Niall Horan and Harry Styles.