Zac Efron ZacEfronHSM3.jpgThere were some scary moments for Zac Efron when a man described as a "deranged fan" attacked the HSM3 star last night in London, according to the UK's Daily Mail.

The paper reports that as Zac was leaving a theater, the man began shouting at Zac and then lunged forward and tried to grab Zac's hair.

Security quickly removed Zac and girlfriend Vanessa Hudgens from the area.

Zac was a little shaken but wasn't injured in the attack. It's not clear at this point what sparked the attack.