Hong Kong police on Friday arrested activist Chow Hang Tung, vice-chairwoman of the group which organises annual vigils for the victims of China's 1989 Tiananmen crackdown on pro-democracy protesters, two of her colleagues said.
The arrest comes as thousands of police are expected to patrol the city's streets to prevent people from gathering to commemorate the June 4 crackdown, in what activists say is a sign of a swift authoritarian turn in Hong Kong.
The heightened vigilance from authorities was a marked departure from Hong Kong's cherished freedoms of speech and assembly, bringing the global financial hub closer in line with mainland China's strict controls on society, they say.
The former British colony, promised a high degree of autonomy from Beijing upon its return to Chinese rule in 1997, has traditionally held the world's largest vigil for the Tiananmen victims.
Chow was arrested for promoting an unauthorised assembly, Chiu Yan Loy, Executive Member of the Hong Kong Alliance in Support of Patriotic Democratic Movements of China, told Reuters in a text message.
"She only wanted to go to Victoria Park, light a candle and commemorate," Chiu said, adding he believed the arrest was meant to strike fear into those planning to attend the vigil.
A police spokeswoman could not immediately confirm the arrest.
Chow, 36, told Reuters this week before her arrest that June 4 was a test for Hong Kong "of whether we can defend our bottom line of morality."
"As long as they haven't said candles are illegal, we will light a candle," she said.
The Alliance's chairman Lee Cheuk-yan is in jail over an illegal assembly.
Police have banned the vigil for a second year in a row, citing the coronavirus. It did not say whether commemorating Tiananmen would breach a sweeping national security law China imposed in 2020 on its most restive city.
City leader Carrie Lam has not commented on commemorations, saying only that citizens must respect the law, as well as the Communist Party, which this year celebrates its 100th anniversary. June 4 commemorations are banned in mainland China.
Last year, thousands in Hong Kong defied the ban, gathering in the downtown Victoria Park and lining up on sidewalks with lit candles across the city, in what was largely a solemn event, bar a brief scuffle with police in one district.
"It is a battle against oblivion," exiled activist Sunny Cheung told Reuters by text.
"For so long, HK has been the only place where (we) can hold vigils to commemorate victims of the 6.4 and that defines HK as the only beacon of liberty and truth under the (Chinese Communist Party's) governance."
"Light a cigarette"
Many plan to light candles again in their neighbourhood, if safe to do so. Some churches will be open for prayers.
Jailed activist Jimmy Sham said via his Facebook page he planned to "light a cigarette at 8pm."
"We do not see the hope of democracy and freedom in a leader, a group, or a ceremony. Every one of us is the hope of democracy and freedom."
Prominent activist Joshua Wong was given a 10-month prison sentence last month after pleading guilty to participating in last year's vigil, while three others got four to six month-sentences. Twenty more are due in court on June 11 on similar charges.
On Wednesday, Hong Kong's June 4th Museum said it would temporarily close due to a licence probe.
The gambling hub of Macau has also banned June 4 activities.
In democratically-ruled Taiwan, a memorial pavilion will be set up in Taipei's Liberty Square, where people can lay down flowers while following social distancing rules. An LED installation of 64 lights will also be set up in the square.
China has never provided a full account of the 1989 violence. The death toll given by officials days later was about 300, most of them soldiers, but rights groups and witnesses say thousands of people may have perished.