Amy Winehouse in scuffle with fan

<div class="meta image-caption"><div class="origin-logo origin-image none"><span>none</span></div><span class="caption-text">The wax figure of British singer Amy Winehouse is unveiled at Madame Tussauds in central London, Wednesday July 23, 2008. &#40;AP Photo&#47;Joel Ryan&#41;</span></div>
June 29, 2008 5:18:40 AM PDT
Amy Winehouse was packing a punch at the Glastonbury music festival.

After taking the stage Saturday, the troubled singer climbed down into the pit and scuffled briefly with a reveler.

It was unclear what sparked the altercation but witnesses say a fan tried to grab Winehouse.

Winehouse sang for about an hour in front of an estimated crowd of 80,000.

She shocked fans last week by performing at a special birthday concert for Nelson Mandela.

The performance came just after she was hospitalized. Her father says she developed emphysema from smoking cigarettes and crack cocaine, although her spokeswoman has said Winehouse only has pre-emphysema symptoms.