BEIJING >> China tightened access to Tiananmen Square in central Beijing on Sunday, the anniversary of the military suppression of 1989 pro-democracy protests that left a still unknown number of people dead and discussions and commemorations forbidden within the country.

In Hong Kong, which was the last Chinese-controlled territory to hold commemorations, eight people, including activists and artists, were detained on the eve of the anniversary, underscoring the city’s shrinking room for freedom of expression. Police said late Sunday they arrested a woman for allegedly obstructing police officers in performing their duties and took 23 other people away on suspicion of breaching public peace for further investigation.

Many of them were detained by officers around Victoria Park, the large public space of lawns and sports grounds that used to be the scene of an annual candlelight gathering to remember the hundreds or thousands killed when army tanks and infantry descended on central Beijing on the night of June 3 and into the morning of June 4, 1989.

Discussion of the seven weeks of student-led protests that attracted workers and artists and their violent resolution has long been suppressed in China. It also became increasingly off-limits in Hong Kong since a sweeping national security law was imposed in 2020, effectively barring anyone from holding memorial events.

The death toll from the 1989 violence remains unknown and the Communist Party relentlessly harasses those at home or overseas who seek to keep the memory of the events alive.

In Beijing, additional security was seen around Tiananmen Square, which has long been ringed with security checks requiring those entering to show identification. People passing by foot or on bicycle on Changan Avenue running north of the square were also stopped and forced to show identification. Those with journalist visas in their passports were told they needed special permission to even approach the area.

Still, throngs of tourists were seen visiting the iconic site, with hundreds standing in line to enter the square.

Ahead of the anniversary, a group of mothers who lost their children in the Tiananmen crackdown sought redress and issued a statement renewing their call for “truth, compensation and accountability.”

Human Rights Watch called on the Chinese government to acknowledge responsibility for the killing of pro-democracy protesters.

“The Chinese government continues to evade accountability for the decades-old Tiananmen Massacre, which has emboldened its arbitrary detention of millions, its severe censorship and surveillance, and its efforts to undermine rights internationally,” Yaqiu Wang, senior China researcher at Human Rights Watch, said in a statement.

While Hong Kong, a former British colony handed over to Chinese rule in 1997, uses colonial-era anti-sedition laws to crack down on dissent, the persistence of non-conforming voices “lays bare the futility of the authorities’ attempts to enforce silence and obedience,” Amnesty International said.

“The Hong Kong government’s shameful campaign to stop people marking this anniversary mirrors the censorship of the Chinese central government and is an insult to those killed in the Tiananmen crackdown,” Amnesty said.

Beijing-appointed authorities in Hong Kong have blocked the Tiananmen memorial for the last three years, citing public health grounds. In 2020, thousands defied a police ban to hold the event.

Despite the lifting of most COVID-19 restrictions, the city’s public commemoration this year was muted under a Beijing-imposed national security law that prosecuted or silenced many Hong Kong activists. Three leaders of the group that used to organize the vigil were charged with subversion under the law. The group itself was disbanded in 2021, after police informed it that it was under investigation for working on behalf of foreign groups, an accusation the group denied.

After the enactment of the security law following massive protests in 2019, Tiananmen-related visual spectacles, including statues at universities, were also removed. Most recently, books featuring the events have been pulled off public library shelves.

Asked whether it is legal to mourn the crackdown in public as an individual, Hong Kong leader John Lee said that if anyone breaks the law, “of course the police will have to take action.”

Many Hong Kongers, who were uncertain what authorities might consider subversive, tried to mark the event in low-profile ways on Sunday.

Chan Po-ying, leader of the League of Social Democrats, held a LED candle in one hand and two yellow paper flowers in another. She was taken away by police officers from a stop-and-search area.

At Victoria Park, scenes of people rallying for democracy have been replaced by a carnival organized by pro-Beijing groups to mark the city’s 1997 handover to China.

By about 8:30 p.m., another 14 people, including activists and a former head of The Hong Kong Journalists Association, were taken away by police in Causeway Bay shopping district, where Victoria Park is located.

Sunday’s events reflected the political chill that has sparked emigration to Britain and other countries and a deep ambivalence among a population that had been strongly engaged in local politics.

The United Nations Human Rights office said on Twitter that it was alarmed by reports of the city’s detention linked to the anniversary, urging the release of anyone detained for exercising freedom of expression and peaceful assembly.

A commemoration was held in Taipei, the capital of the self-governing island democracy of Taiwan, which China claims as its own territory to be annexed possibly by force. More than 500 participants turned out to light candles, hear speeches and chant slogans under a heavy rain.

Kacey Wong, an artist who is among the scores of Hong Kong residents who have moved to Taiwan, said the more than 30 years of commemorating the 1989 protests had made it a part of life.

Wong said an artist friend, Sanmu Chen, had been detained along with others while attempting to stage a public street performance in Causeway Bay in Hong Kong.

“So, it’s all engrained in our subconscious that we should care and practice our sympathy towards other people who are yearning for democracy and freedom,” Wong said.