Chinese police aggressively deterred dissent on Thursday's 20th anniversary of the crackdown on democracy activists in Tiananmen Square, ignoring calls from Hillary Rodham Clinton and even Taiwan's China-friendly president for Beijing to face up to the 1989 violence.
Foreign journalists were barred from the vast square as uniformed and plainclothes police stood guard across the area which was the epicenter of the student-led movement that was crushed by the military on the night of June 3-4, 1989.
Security officials checking passports also blocked foreign TV camera operators and photographers from entering the square to cover the raising of China's national flag, which happens at dawn every day. Plain clothes officers aggressively confronted journalists on the streets surrounding the square, cursing and threatening violence against them.
The extraordinary security moves come after government censors shut down social networking and image-sharing Web sites such as Twitter and Flickr, and blacked out CNN and other foreign news channels each time they aired stories about Tiananmen.
Dissidents and families of crackdown victims were confined to their homes or forced to leave Beijing, part of sweeping efforts to prevent online debate or organized commemorations of the anniversary.
"We've been under 24-hour surveillance for a week and aren't able to leave home to mourn. It's totally inhuman," said Xu Jue, whose son was 22 when he was shot in the chest by soldiers and bled to death on June 4, 1989.
Officers and police cars were also stationed outside the home of Wang Yannan, the daughter of Zhao Ziyang, the Communist Party leader deposed for sympathizing with the pro-democracy protesters, according to the Hong Kong-based Information Center for Human Rights and Democracy. Wang heads an auction firm and has never been politically active.
In a further sign of the government's intransigence, the second most-wanted student leader from 1989 was forced to return to Taiwan on Thursday after flying to the Chinese territory of Macau the day before in an attempt to return home.
Wu'er Kaixi, in exile since fleeing China after the crackdown, told The Associated Press by phone he was held overnight at the Macau airport's detention center and that being denied entry on the Tiananmen anniversary was a "tragedy."
The student leader who topped the most-wanted list, Wang Dan, was jailed for seven years before being expelled to the United States in 1998.
In Washington, U.S. Secretary of State Clinton said in a statement Wednesday that China, as an emerging global power, "should examine openly the darker events of its past and provide a public accounting of those killed, detained or missing, both to learn and to heal."
Taiwanese President Ma Ying-jeou urged China to lift the taboo on discussing the crackdown.
"This painful chapter in history must be faced. Pretending it never happened is not an option," Ma said in a statement issued Thursday.
Chinese Foreign Ministry spokesman attacked Clinton's comments as a "gross interference in China's internal affairs."
"We urge the U.S. to put aside its political prejudice and correct its wrongdoing and refrain from disrupting or undermining bilateral relations," Qin said in response to a question at a regularly scheduled news briefing.
Qin refused to comment on the security measures — or even acknowledge they were in place.
"Today is like any other day, stable," he said.
Beijing has never allowed an independent investigation into the military's crushing of the protests, in which possibly thousands of students, activists and ordinary citizens were killed. Young Chinese know little about the events, having grown up in a generation that has largely eschewed politics in favor of raw nationalism, wealth acquisition, and individual pursuits.
Authorities have been tightening surveillance of China's dissident community ahead of the anniversary, with some leading writers under close watch or house arrest for months.
Ding Zilin, a retired professor and advocate for Tiananmen victims, said by telephone that a dozen officers have been blocking her and her husband from leaving their Beijing apartment.
In contrast to the repression on the mainland, tens of thousands of people were expected to attend an annual candlelight vigil in the former British colony of Hong Kong, which has maintained its own legal system and open society since reverting to Chinese rule in 1997.