Illness has forced Avicii to cancel a series of appearances in Miami, including a headlining slot at Ultra Music Festival on Saturday.

"He has been diagnosed as having a blocked gall bladder," his publicist revealed Friday (March 28) evening, "and is currently being evaluated for a potential surgery to remove his gall bladder. ... He has had to cancel all his commitments for the week," they add via email, "including a highly anticipated performance last night at the Ushuaia Pop Up at the Avicii Hotel at SLS and his headline performance  tomorrow at the ULTRA Music Festival."

Ultra announced Friday evening that Deadmau5 would replace Avicii on the bill. Avicii later posted a letter to fans on his Facebook page revealing that he would undergo gall bladder surgery on Saturday morning. It reads, in part: "My fans know that I have had issues in the past with my stomach and pancreatitis…I woke up on Wednesday morning with serious pain but I flew to Miami anyway, hoping that it would go away. The pain was still there when I landed so I went straight to hospital. I was treated and left later that night. Unfortunately, the pain came back yesterday afternoon and I returned to the hospital where they admitted me to stay overnight."

The Swedish DJ, born Tim Bergling, was scheduled to play a show at SLS South Beach in Miami Beach on Thursday, but shortly before he was supposed to perform, Australian duo Cazzette informed the crowd that he would not be playing, citing his trip to the hospital.

"At the hospital," Avicii said in a since-deleted message on Twitter. "Extremely bummed about missing my show at the Avicii Hotel. My brother @Alesso is stepping up and covering for me."

Thursday's show was to be the second of a five-night set at the Miami hotel, which Avicii confirmed last month as the newest iteration of his Avicii Hotel series.

TMZ was first to report the DJ's hospitalization. The site later said the DJ had left the hospital.

This article was first published 03-27 at 21:53. It was updated Friday morning and evening with new information.