"How has the world become like this? I don't even have one bit of power. Why must we be controlled so strictly this year?" Yin said in a telephone interview. "I looked at his ashes, I looked at his old things, and I cried bitterly."
China allows no public discussion of the events of June 3-4, 1989, when soldiers backed by tanks and armored personnel carriers fought their way into the heart of Beijing, killing hundreds, possibly thousands, of unarmed protesters and onlookers.
On Wednesday, scores of police and paramilitary troops patrolled the vast plaza and surrounding streets in Beijing's heart, stopping vehicles and demanding identification from passers-by. Chinese censors scrubbed domestic blogs and social media websites of comments marking the crackdown.
The silence in the mainland about the anniversary of a pivotal event that shocked the world contrasted with boisterous commemorations in Hong Kong.
Large crowds gathered Wednesday night in the city's Victoria Park for an annual candlelight vigil to remember the Tiananmen victims, holding candles aloft that turned the vast area into a sea of flickering light.
Activists laid a wreath at a makeshift memorial as the names and biographical details of people killed in the crackdown were read out. Organizers said more than 180,000 people took part, with many overflowing into the streets around the park's main entrance.
Elsewhere, U.S. Secretary of State John Kerry urged China to release those jailed in connection with the events. "For all people who seek freedom, Tiananmen Square still stirs our conscience," he said in a statement.
Some relatives of the crackdown's victims in Beijing were allowed to pay their respects at cemeteries — but only with police escorts. Others did so at home under surveillance, expressing frustration at the restrictions placed on their remembrances.
"I told my son this morning, 'Your mother is powerless and helpless, after more than 20 years I don't even have the chance to appeal for support,'" said Yin, whose 19-year-old son, Ye Weihang, was killed in the crackdown. Police have kept a round-the-clock surveillance of her home since April, she said, and the relatives' hopes of gathering and holding a public commemoration were dashed.
"You're not only re-opening my scars, you're spreading salt and chili powder into them," Yin said she told her minders.
The Chinese government has largely ignored the relatives' demands for an admission of wrongdoing and for a complete, formal accounting of the crackdown and the number of casualties. Beijing's verdict is that the student-led protests aimed to topple the ruling Communist Party and plunge China into chaos. Protest leaders said they were seeking broader democracy and freedom, along with an end to corruption and favoritism within the party.
Near the square in Beijing, reporters were told to leave following the daily crack-of-dawn flag-raising ceremony and there were no signs of demonstrations or public commemorations. Dozens of dissidents and other critics have already been detained by police, held under house arrest or sent out of the city in what they say is a more restrictive clampdown than usual reflecting the increasingly conservative political atmosphere under President Xi Jinping.
On normal days, the vast plaza is closely watched by surveillance cameras and plainclothes police and officers riding Segways, but most people are allowed to enter without having their IDs checked. Wednesday's measures, including the deployment of hundreds of security and emergency services personnel, were a dramatic tightening.
Authorities allowed about a dozen relatives of four people killed in the crackdown to pay their respects at a cemetery in Beijing, but they were under police escort and were watched by several dozen plainclothes officers, according to Zhang Xianling, a member of a group that campaigns for the crackdown's victims.
The relatives laid flowers and bowed three times as is customary in Chinese mourning, Zhang said, and one of them read from a prepared text.
"A quarter of a century has passed since the June 4, 1989, massacre. In these endless 25 years, not a moment has gone by that we didn't miss you," said the text, provided by Zhang to the AP.
"Our tears have run dry, our voices are already hoarse," it said. "Our temples have grayed, our gaits are already faltering. With the passage of time, we will bury our sorrow deep in our hearts and strengthen our faith and determination to pursue justice."
Activist lawyer Teng Biao said the government's repression only betrayed its frailty and fear of dissent. "Although the government appears stronger, they are more fearful, less confident and have less sense of security," Teng said from Hong Kong, where he is a visiting scholar at the city's Chinese University.
Foreign media in Beijing have been warned not to meet with dissidents or report on issues related to the anniversary. In an unusual burst of activity, the Foreign Ministry and Cabinet office held news conferences and called in Associated Press reporters for meetings Wednesday.
In Hong Kong, the Tiananmen protests remain a totem for political expression and Western-style civil liberties in the former British colony that retained its own liberal social and legal systems after reverting to Chinese rule in 1997.
"The reason that I've come here is that I want to see the sunshine of freedom," said Rany Cao, a 30-year-old mainland Chinese electronics importer based in Hong Kong who joined the Wednesday night vigil.
"I can feel that there's something about Hong Kong that is different from China, and that is, people are striving for freedom, striving for democracy," Cao said. "I expect to learn more about the truth of what happened 25 years ago."
For the first time, a pro-Beijing group, the Voice of Loving Hong Kong, was planning a counter-rally at the park's entrance in support of the military crackdown, in a sign of increasing polarization in the former British colony.
Along with concerns about political unrest, China has recently been shaken by violence blamed on separatists from the far northwestern region of Xinjiang, adding to the increased security measures.
Associated Press writers Christopher Bodeen and Didi Tang in Beijing and Kelvin Chan and researcher Theodora Yu in Hong Kong contributed to this report.
Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.