Hong Kong police on Friday closed off large parts of Victoria Park, once the site of packed annual candlelight vigils to commemorate China's Tiananmen crackdown, on the eve of the event's 33rd anniversary.

In the past, huge crowds would routinely gather in the large public space to pay tribute to victims of the Chinese government's 1989 clampdown, when soldiers brutally quashed peaceful demonstrations demanding political and economic reform.

The late-night closure comes a day after authorities warned people that going to the park on the anniversary -- even alone -- could put them at risk of breaking the law.

A heavy police presence was visible in the area on Friday evening.

In the nearby bustling Causeway Bay shopping district, a performance artist who whittled a potato into the shape of a candle and held a lighter to it was surrounded by more than a dozen officers and taken away in a police van, an AFP reporter saw.

Public commemorations of Tiananmen are all but forbidden in mainland China.

Semi-autonomous Hong Kong had been the one place in the country where large-scale remembrance was still tolerated -- until Beijing imposed a wide-reaching national security law two years ago, in reaction to citywide pro-democracy protests.

The imposition of the security law has swiftly driven Tiananmen commemoration underground.

The artist who was taken away by police, Chan Mei-tung, was one of three who were giving street performances that obliquely referenced Tiananmen near one of the busiest intersections in the city on Friday evening.

One artist invited passers-by to complete a "math challenge" where the solution came to 8,964, a reference to the date June 4, 1989.

Another artist, Sanmu Chan, presented an abstract piece which included a candle frozen within a small block of ice.

The artists were closely watched by the police, who broadcast warnings that onlookers might be at risk of breaching social distancing laws.

Police did not immediately respond to a request for comment regarding the detention of the artist at the scene.

Hong Kong police said that most gathering spaces in the park will be closed between Friday night and early on Sunday
Hong Kong police said that most gathering spaces in the park will be closed between Friday night and early on Sunday AFP / DALE DE LA REY

Earlier on Friday, authorities said they had arrested a 59-year-old security guard on suspicion of making threats on social media about killing officers at commemoration events.

Police said the investigation was ongoing.

Hong Kong authorities said Friday that most gathering spaces in Victoria Park -- including the football pitches used for the candlelight vigil in previous years -- will be closed between Friday night and the early hours of Sunday.

The decision was made "in order to prevent any unauthorised assemblies in the park which affect public safety and public order, and the chance of a virus spread due to such gatherings", a spokesperson said.

The vigil had been banned in 2020 and 2021 as well, with police citing a ban on gatherings under anti-coronavirus rules.

All major organisers of Hong Kong's Tiananmen events have suspended their efforts this year, but police claimed there were still calls for people to join gatherings at the park and in surrounding areas.

On Friday night, Hong Kong police warned the public that "participating in an unauthorised assembly" risked breaking the law, and carried a maximum penalty of five years' imprisonment.

The Hong Kong Alliance, one of the main organisers of the Victoria Park vigil, disbanded last September and its leaders are being prosecuted for subversion.

Jailed former alliance leader Lee Cheuk-yan said in a letter that he planned to fast on June 4, and that he would light a match and sing commemorative songs in his jail cell.

"I believe that Hong Kongers will join me in commemorating June 4 as a matter of sincere belief, using their own ways to express their remembrance and their commitment to democracy," Lee wrote in a letter published online on Friday.

In the neighbouring city of Macau, former opposition lawmaker Au Kam-san said democrats will not hold a Tiananmen vigil this year due to the "worsening environment in Macau politics", adding that a historical exhibition will also be cancelled.

Au said he will light a candle on June 4 and broadcast it live on Facebook as a sign of his perseverance.