Activist is stopped and searched by police officers during a pro-democracy protest by the League of Social Democrats during the government flag raising ceremony in Hong Kong on July 1. Photo: AFP / Miguel Candela Poblacion / Anadolu Agency

Police were out in force across Hong Kong on Thursday, ready to stamp down on any sign of dissent as China’s Communist Party celebrated its centenary, in a vivid illustration of how the once-outspoken finance hub has been successfully muzzled.

The grand celebrations in Beijing coincided with the 24th anniversary of Hong Kong’s 1997 handover to China by colonial Britain.

Since 2003, Hong Kongers have regularly filled the streets each handover anniversary with marches and rallies.

But protest has been all but banned in Hong Kong as China carries out a sweeping crackdown against its opponents after huge and often violent pro-democracy rallies convulsed the city two years ago.

More than 10,000 officers – one third of the city’s force – were deployed to prevent any public gatherings, local media reported, as officials warned that any attempt to protest would lead to arrest.

With Hong Kong’s chief executive Carrie Lam attending the festivities in Beijing, her deputy John Lee oversaw a flag-raising ceremony in an exhibition center as police and water cannon trucks patrolled streets nearby.

Lee delivered a speech praising China’s imposition of a sweeping national security law in Hong Kong, which came into effect just an hour before last year’s handover anniversary.

“While safeguarding national security, residents continue to enjoy freedom of speech, freedom of press, freedom of assembly and demonstration and others according to the law,” Lee said.

Such assurances are repeatedly made by Hong Kong’s leaders.

Over the last year the national security law has criminalised a host of political views and transformed semi-autonomous Hong Kong’s political and legal landscape.

Protest has been effectively outlawed, and many of the city’s opposition leaders are arrested and jailed or have fled overseas.

Last month the city’s most outspoken pro-democracy newspaper Apple Daily shut down after its accounts were frozen under the national security law and multiple employees were arrested over articles the popular tabloid published.

Public gatherings of more than four people remain outlawed under anti-coronavirus measures, although the city currently has no active local outbreak.

On Wednesday, prominent human rights barrister Chow Hang-tung was arrested and charged with inciting others to join an illegal protest last month.

The only visible protest on Thursday morning was carried out by four activists from the League of Social Democrats, one of the few opposition parties still operating.

They held a banner near the official reception calling for the release of political prisoners.

Some 200 police officers followed their lonely march and stopped the group from getting too close to the exhibition center where dignitaries were gathered.

“Police are acting as if they are facing some enormous enemy,” Raphael Wong, one of the activists, told reporters.