Kelly Clarkson has defended Pink against her critics.

The 'So What' hitmaker was left upset at having to cancel a concert - part of her ongoing The Truth About Love world tour - in Birmingham, middle England, recently after being struck with the illness and when some fans hit out at her, Kelly took to her WhoSay page to defend the singer.

She sarcastically wrote: ''@pink how dare you only work 364 days this year. I can't believe you got sick. That never happens to anyone....ever. You're so lazy #nameonepersonthathasherschedule,singswhileflying,andisamom ....seriously people. Tired of seeing everyone giving her crap. We're all human. Relax (sic).''

Pink recently reached out to her fans in a series of posts on Twitter, to explain what happened.

She wrote: ''With deepest regrets I had to cancel my first show of the tour tonight in Birmingham. I have an ear and respiratory infection. I am not a person that takes cancellations lightly and I apologize to anyone who was inconvenienced by my illness.

''Thanks to all my genuine people out there sending love (sic).''

The 33-year-old star also had a statement published on her official website, which read: ''It is with great regret that P!nk has been forced to postpone her concert tonight at Birmingham's LG Arena. After seeking medical advice this afternoon she has been advised that she cannot perform tonight.

''The promoters have asked ticket holders for tonight's show to retain their tickets. Further announcements regarding a replacement date will follow.

''All other UK dates on 'The Truth About Love Tour' will not be affected.''