As night fell, candles appeared in the windows of several foreign countries’ missions to Hong Kong — in defiance of a warning not to do so — and on various street corners around the city.

Discussion of the events of 1989, when China set troops and tanks on peaceful protestors, is all but forbidden on the mainland.

Semi-autonomous Hong Kong had been the one place in China where large-scale remembrance was still tolerated — until two years ago when Beijing imposed a national security law to snuff out dissent after widespread pro-democracy protests in 2019.

Authorities had warned the public that “participating in an unauthorised assembly” on Saturday risked a maximum penalty of five years’ imprisonment.

They also closed large parts of Victoria Park, once the site of packed annual candlelight vigils that were attended by tens of thousands on the anniversary.

The park and nearby Causeway Bay shopping district — one of the city’s busiest neighbourhoods — were heavily policed all day.

People were stopped and searched for carrying flowers, wearing black and, in one case, carrying a toy tank box.

Reporters saw at least half a dozen people being taken away by police, mostly in the evening, including activist Yu Wai-pan from the League of Social Democrats (LSD) party.

LSD said Yu was later released without charge, while fellow member Lau Shan-ching was arrested for wearing a shirt with a portrait of late Chinese democracy activist Li Wangyang wearing a mask that read “mourn June 4”. “For 33 years it has always been peaceful, but today it’s like (police) are facing a big enemy,” Chan Po-ying, head of the LSD, said.

Security was heightened in the Chinese capital Beijing on Saturday, with officer numbers bulked up, and ID checks and facial recognition devices set up on roads leading to Tiananmen Square.

China has gone to exhaustive lengths to erase the crackdown from collective memory, omitting it from history textbooks and scrubbing references to it from the Chinese internet and social media platforms.

A similar approach is now beginning to be applied to Hong Kong, as authorities remould the city in the mainland’s image.

Since last September, the Victoria Park vigil’s organisers have been arrested and charged with subversion, their June 4 museum has been closed, statues have been removed and memorial church services cancelled. Commemoration events in Macau were also cancelled this year.

On Saturday, multiple Western consulates general in Hong Kong posted Tiananmen tributes on social media, despite local media reports that they had been warned by the city’s Chinese foreign ministry office to refrain from doing so.

The European Union’s office confirmed that they had received a call. At dusk, both the US Consulate General and the EU office’s windows were illuminated by the flickering light of candles.