Niall Horan has successfully undergone "major knee surgery".
The One Direction star has asked fans to "respect" his privacy as he starts to recover from the operation, but he refused to go into detail on the matter.
Writing on Twitter, he revealed: "Hey guys I know most of you have seen those pics today! Yes I've had major knee surgery , a much larger surgery than first anticipated.
"But i would like to tell u , it was a complete success ! Considering the scale of it! So all I ask of you guys is that you would respect my privacy as I try to recover and get for the where we are tour! (sic)"
Recently, the 'Story of My Life' hitmaker clashed with fans on the micro-blogging website after users created fake accounts posing as his parents.
Niall tweeted to ask them to "stop", describing the false profiles of mother Maura Gallagher and father Bobby Horan as "freaky".
"My brother and Denise are the only ones with twitter so any of you pretending to be my parents! Stop ! It's actually really freaky! (sic)"