Maybe Bieber has the fever?

It wasn't just Justin Bieber's fans who had "Bieber Fever" as the teen idol kicked off his latest national tour in a Phoenix suburb, The Associated Press reports.

Video posted on local KTVK-TV's website shows the pop music star vomiting twice on stage Saturday night during his sold-out concert at the Jobing.com Arena in Glendale.

He left the stage after each episode but returned and even did an encore.

"It's hard for me, you know, not feeling great and throwing up in front of a bunch of people," he told the crowd after leaving the stage during his song "Beauty and a Beat," according to USA Today. "Will you love me even though I'm throwing up on stage?"

KTVK reports Bieber's fans sang some of his songs while he was offstage.

Bieber later tweeted "Great show. Getting better for tomorrow's show !!!! Love u" He later added, in a nod to the 2004 comedy "Anchorman": "And . . . Milk was a bad choice!"

Bieber's 45-city "Believe" tour continued last night in Las Vegas, at the MGM Grand Garden Arena.