Tens of thousands of people dressed in funereal black or white gathered in a central park in Hong Kong and lit candles Friday night to mark the 15th anniversary of the Tiananmen Square massacre and protest the Chinese government's hard line against democratic reform in this former British colony.

The vigil was the only public commemoration of the June 4, 1989, military crackdown permitted in China. In Beijing, police thwarted several attempts to mark the anniversary, dragging away more than a dozen unidentified people from Tiananmen Square and keeping many dissidents and relatives of those slain in 1989 under surveillance or house arrest.

The contrast between the security clampdown in the Chinese capital and an emotional, two-hour candlelight vigil here highlighted the special freedoms that the people of Hong Kong enjoy -- and the thorny challenge that their demands for greater democracy continue to pose to the ruling Chinese Communist Party.

Police estimated that 48,000 people attended the demonstration in Victoria Park, but organizers put the figure at 82,000, the largest turnout since the event was first held in 1990 and a sharp increase over the 50,000 who participated last year.

In previous years, the June 4 vigil focused on mourning the hundreds, perhaps thousands, killed when Chinese troops and tanks suppressed student-led, pro-democracy demonstrations in Tiananmen Square in 1989. But this year, participants also linked the vigil to Hong Kong's own struggle for democracy.

"China's brutal suppression of Hong Kong's democracy is like a June 4 crackdown without blood," said Bishop Joseph Zen, the head of the Roman Catholic Church in Hong Kong and an outspoken supporter of democratic reforms.

Emotions have been running high since April, when Beijing rejected popular demands for direct elections in 2007 and 2008 to choose the territory's next chief executive and all its legislators. Pro-democracy activists have vowed to keep fighting and are planning a major demonstration on July 1, the anniversary of the territory's 1997 return to Chinese rule and an anti-government rally that drew 500,000 people last year.

"We included the theme of democracy this year because without a government that is responsible to the people, the community can have no hope and no future," said Szeto Wah, a lawmaker who is a veteran of the pro-democracy movement and the vigil's chief organizer. "Democracy is also the spirit of the 1989 student movement."

Waving candles and singing, the crowd filled an area of six soccer fields and carried signs that urged people to both "Remember June 4" and "March on July 1." Many participants wept quietly when footage of the 1989 massacre was shown on a large screen under a banner that declared, "Return Power to the People." But then the crowd began chanting "End Communist rule" and "Free the dissidents," and the roar echoed through the glitzy streets of the nearby Causeway Bay shopping district.

The Chinese government maintains that the Tiananmen Square crackdown was necessary to ensure social stability, which in turn made possible the country's historic economic growth over the past 15 years.

In recent months, Beijing has made it easier for mainland tourists to visit Hong Kong, part of a strategy to boost the territory's slumping economy and win over public sentiment. But pro-democracy activists passed out fliers and persuaded many tourists to attend the vigil.

Some who did, like Xie Chunyong, 36, an office manager from southern Guizhou province, had never seen footage of the Tiananmen killings. "In China, I had only heard about the incident," she said. "Hong Kong people are lucky. They can know the truth. . . . I admire their courage."

In another development certain to alarm Chinese officials, members of a pro-Taiwan organization raised a Taiwanese flag during the vigil. "Chinese in Taiwan can vote for their president," said Tang Man-chun, 29, of the China Youth Services and Recreation Center. "It is a shame that we people in Hong Kong cannot have the same rights, even after returning to the so-called motherland."

Lee Cheuk-yan, a pro-democracy lawmaker, said the large turnout at the vigil reflected growing anger that Beijing is breaking its promise to give Hong Kong a high degree of autonomy and is trying to influence the results of legislative elections in September. Pro-democracy candidates hope to win a majority that could be used to block government legislation and force concessions from China on democratic reform.

But three popular radio talk show hosts critical of the Chinese government have quit their jobs in the past month, claiming they had received threats authorized by Beijing.

"China has started stretching its hands into Hong Kong," said Lai Man-heung, 30, who arrived at the vigil in a wheelchair. "It banned our democracy. It's time for us to come out and show our anger."

Pan reported from Beijing.

A candlelight vigil in Hong Kong was the only public commemoration that China allowed to mark the June 4, 1989, crackdown at Tiananmen Square.