It was the first large demonstration on Chinese soil over the killings in Beijing nine years ago. Britain returned Hong Kong to China last July.

Hong Kong residents laid wreaths and held a candle-lit vigil in memory of the hundreds of demonstrators who were killed in 1989.

Democracy activist Wang Dan was recently released into exile

Pro-democracy activists called on Beijing to admit its mistake in sending in the army to crush the unarmed students.

The Chinese dissident, Wang Dan, who was a leader of the 1989 protest, told the crowd that he was "touched" by the large turnout.

He was speaking by telephone hookup from the United States, where he was sent after his release from a Chinese prison in April.

'A mix of pragmatism and fear'

BBC's Jill McGivering: 'Hong Kong has become a focal point for protest'

However, the turnout does not match the 55,000 people who marked the anniversary last year, three weeks before Britain returned Hong Kong to Chinese rule. The BBC Hong Kong correspondent says one recent opinion poll suggests that public outrage about the killings is mellowing.

But according to former BBC Beijing bureau chief Humphrey Hawksley, the people of Hong Kong are motivated by "a mix of pragmatism and fear" in staying away from the demonstration.

"Anyone going out on that march now will be photographed by the Chinese security forces and that photograph will be kept on a file."

But government spokesman, Paul Brown says protestors would not be photographed: " Hong Kong is a free and open society where freedom of expression and assembly is protected by law. Some 1,400 demonstrations have taken place since 1 July 1997 and the police have not objected to or prohibited a single one."

He adds that: "the policing of Hong Kong is entirely the responsibility of the Hong Kong Police, and not Chinese security forces."

Hong Kong's democracy movement won a major victory in elections last month when pro-democracy politicians took two-thirds of directly-elected seats.

Many of the newly-elected politicians are calling for a faster pace of democratic reform in Hong Kong, and for greater political freedom on the mainland.

Security tight

Elsewhere in China, opposition groups say police warned dissidents not to stage protests before President Clinton's visit to China this month, and security is tight in the capital, Beijing.

China is on security alert.

About two dozen dissidents were rounded up around the country in the run-up to the anniversary.

However, no major incident was reported in Tiananmen Square itself, which was filled with tourists taking photographs as usual.

A wheelchair-bound protester and his brother who were scattering leaflets in the middle of the square were quickly arrested. They were airing a personal grievance - nothing to do with 1989.

Two foreign journalists were also briefly detained.