Bieber Fever has spread down under.

Justin Bieber's brief promotional visit has become big news across Australia after several fans were crushed while jostling for a view of the teenage pop superstar.

Bieber was meant to sing three songs for the free-to-air Channel Seven's "Sunrise" program this morning (April 26), but police pulled the plug because of safety concern.

The authorities took the hard-line approach when thousands of youngsters amassed in the early hours of this morning to catch Bieber's set in front of the Overseas Passenger Terminal at Sydney's Circular Quay. By 3am, the crowd had grown to about 3,000 fans, most of them teenage females.

Later, as the audience surged forward a number of onlookers were injured and the safety barriers were breached. Eight fans were reportedly taken to hospital after being crushed in the crowd, and dozens more were treated on-site for hyperventilation.

The Canadian singer performed just one song and he delivered it behind the glass of Channel Seven's studio, as the amassed throng whipping up a frenzy behind him.

Deputy police commissioner Dave Owens said the situation was threatening to spiral out of control, and he said the parents ought to take much of the blame.

"There were a number of parents down there [but] I would question why there weren't a larger number of parents," he said. "We had 12, 13 and 14-year olds [alone] at 3 and 4am in the morning. They were being crushed up against the barrier."

Bieber's gold-certified (35,000 units) single "Baby" (Universal Music Australia) is currently No. 10 on the ARIA singles chart. His album "My Worlds" was released April 23 down under.