By Mark O'Neill

BEIJING, Sep 8 (Reuter) - China's tight security regained the spotlight on Friday when police briefly detained a Hong Kong television crew after a scuffle during the presentation of a human rights petition at the U.N. women's conference in Beijing.

Charges of heavy-handed police harassment of participants at a grassroots forum running parallel to the United Nations Fourth World Conference on Women and intense surveillance have marred meetings that aim to chart a course for women's rights and equality over the next decade.

The three-member television crew from Hong Kong's TVB station were grabbed by plainclothes security men who dragged them along a street leading out of the site of the U.N. women's conference.

China's official Xinhua news agency said the incident erupted when cameraman Au-Yeung Cham hit a Chinese site volunteer staffer who was trying to prevent the protest march from obstructing traffic, on the head, chest and back with his tripod and camera.

All three, including reporter Tammy Tam and a soundman, shouted and struggled as they were pulled along the street by more than a dozen police, witnesses said.

Three policemen holding the sound man locked his arm behind his back when he tried to break away, witnesses said.

All three were pushed into an unmarked white van.

They were taken to a police station and released after a brief interrogation, Tammy Tam said.

They had official accreditation from the United Nations to cover the conference. No other reporters covering the presentation of the petition to the United Nations High Commissioner on Human Rights were treated similarly.

A spokesman for the United Nations said the incident took place in an area outside the main conference buildings, which fall under U.N. jurisdiction during the meeting, adding that he had been informed the scuffle was started by the cameraman.

The U.N. had no plans to lodge a protest, spokesman Thomas Netter said.

However, the incident refocused the spotlight on the stringent security with which China has surrounded the two meetings.

The security measures drew criticism from U.S. First Lady Hillary Rodham Clinton during an address to the conference plenary session on Tuesday, when she said China's bid to limit debate at a U.N. conference on women was "indefensible."

Clinton drew prolonged applause from the mostly female delegates when she complained about the treatment of women attending the non-government forum that is part of the U.N.-sponsored event.

Many who wanted to participate in the sessions, held once every 10 years, said they had been denied visas, while others -- mainly Tibetan exiles, human rights activists and lesbians -- said they had been harassed by police and were under surveillance when they reached the event in suburban Beijing.

Others have complained that media attention on the harassment of a small minority of the 25,000 people attending the grassroots forum had distracted attention from the main task at hand -- the battle for women's rights and equality.