Justin Bieber trips up on stage

Justin Bieber took a tumble live onstage while performing for his Believe world tour in his native Canada.

The 18-year-old pop sensation was joined on stage in Saskatoon by his protege Carly Rae Jepsen to sing their duet Beautiful.

But towards the end of the track, ironically while he was singing "nobody's perfect", Justin tripped down the stairs and landed on his behind. Luckily, Call Me Maybe star Carly Rae was there, holding his hand, and he jumped straight back up and carried on.

But fans didn't miss the mistake and video has been posted online.

Later Justin tweeted: "on the bus thinking about how incredible the last few shows have been. proud to be canadian! thanks for having me. see u again real soon."

The trip comes just two weeks after Justin was taken ill and vomited twice on stage during his sold-out concert in Phoenix. He left the stage after each episode and apologised to the crowd but carried on with the show.