POP superstar Justin Bieber had his army of adoring fans fretting after he twice vomited during a concert at the weekend.
The singer (18) suffered his very own form of 'Bieber fever' during the first show of his US tour in suburban Phoenix, Arizona.
The cute singer succumbed to an upset stomach not once but twice during his 21-song set, leaving fans wide-eyed and concerned.
Video posted on a news website showed the pop music star vomiting twice on stage at the weekend during his sold-out concert.
He left the stage after each episode but returned and even sang an encore.
Bieber later tweeted: "Great show. Getting better for tomorrow's show !!!! Love u."
He later revealed the cause of his upset stomach was nothing more serious than the wrong choice of beverage.
"And . . . Milk was a bad choice!" he added.
Bieber's 45-city Believe tour has continued despite the illness scare and he is currently playing dates in Las Vegas.
He is due to play in Dublin in February 2013.
Bieber's girlfriend Selena Gomez recently revealed how the star adores visiting Disneyland.
"We go to Disneyland a lot, he likes it, but we go to Knott's Scary Farm (an event at Knott's Berry Farm in California) because that's my favourite," Gomez said. "I'm the kind of person that likes to get scared -- but I'm covering my eyes and ears the entire time," she added.
The couple have been dating each other for past 18 months.