Justin Bieber's fans knocked over his mother as they mobbed him at a New Zealand airport last night (27.04.10).

The Canadian teen sensation was rushed through the terminal building to escape hoards of screaming teenagers, who stole his hat as they stampeded.

He later tweeted: "Finally got to New Zealand last night. The airport was crazy. Not happy that someone stole my hat and knocked down my mama. Come on people."

'Baby' singer Justin's mother wasn't hurt when she was knocked over, and later tweeted fans to say she was OK.

She wrote: "Thanks for all ur support!! I'm ok thank you!!!(sic)"

Police told the singer to axe plans to sign autographs and take pictures with fans amid fear the crowd would get further out-of-control, prompting many of the waiting group to burst into tears.

However, most of the waiting supporters were just delighted to have caught a glimpse of their idol.

Fan Tory Shaffett said: "Oh my god, he was so amazing and beautiful. I can't believe I saw him."

Justin later implored fans to calm down or face other signing opportunities being scrapped.

He tweeted: "I want to be able to sign and take pics and meet my fans, but if you are all pushing security wont let me. let's keep it safe and have fun. (sic)"

Hoards of teenage fans also forced the cancellation of a scheduled appearance by the 16-year old star in Sydney, Australia, earlier this week.

Police reported "mass scenes of hysteria" and 10 girls fainted as they waited through the night to watch their idol perform. Paramedics treated the injured on the scene, and the worst injury was to one fan who fractured their kneecap.