Dozens of democracy supporters were arrested in Hong Kong Thursday for defying a protest ban as the city marked China's National Day and its leader hailed Beijing's new security law for restoring stability to the restive finance hub.

The People's Republic of China celebrates its founding on October 1 with a holiday and carefully choreographed festivities.

A police source told AFP that 6,000 police officers had been drafted in to stop any protests
A police source told AFP that 6,000 police officers had been drafted in to stop any protests AFP / DALE DE LA REY

But in Hong Kong, it has become a day of grievance for those worried about authoritarian Beijing's intensifying crackdown against its opponents.

Protest has been effectively outlawed for most of this year due to coronavirus restrictions on gatherings and Beijing also imposed a strict national security law on the city in June.

Hong Kong Chief Executive Carrie Lam hailed her city's 'return to peace'
Hong Kong Chief Executive Carrie Lam hailed her city's 'return to peace' AFP / Jayne Russell

Helicopters flying the Chinese and Hong Kong flags buzzed over the harbour on Thursday morning as Chief Executive Carrie Lam and senior mainland officials attended a ceremony ringed by police and security barriers.

"Over the past few months, an indisputable fact in front of everyone is that our society has returned to peace," Lam said in her speech.

"Our country's national security has been protected in Hong Kong and our citizens can again exercise their rights and liberties in accordance with laws."

Activists from the League of Social Democrats, including Leung Kwok-hung, also known as 'Long Hair' (2nd L), take part in a demonstration as police follow closely during China's National Day in Hong Kong
Activists from the League of Social Democrats, including Leung Kwok-hung, also known as 'Long Hair' (2nd L), take part in a demonstration as police follow closely during China's National Day in Hong Kong AFP / May JAMES

But throughout the day officers swooped on the few people who dared to protest.

Police said more than 80 were arrested, mostly for "unlawful assembly". Officers also raised banners warning crowds that they were breaching the national security law with their protest chants.

Hong Kong Chief Executive Carrie Lam and other officials attend a flag raising ceremony to mark China's National Day in Hong Kong
Hong Kong Chief Executive Carrie Lam and other officials attend a flag raising ceremony to mark China's National Day in Hong Kong AFP / Jayne RUSSELL

Last year's National Day, the PRC's 70th anniversary, brought fierce clashes between protesters and police during seven months of democracy demonstrations that upended Hong Kong.

Authorities denied permission for a protest march this year, citing security concerns and an anti-coronavirus ban on more than four people gathering in public.

Police stop pedestrians as they patrol to deter protests during China's National Day in Hong Kong
Police stop pedestrians as they patrol to deter protests during China's National Day in Hong Kong AFP / May JAMES

Lam's administration also suspended September local elections for a year -- one of the few occasions when Hong Kongers can cast a vote -- citing the risk posed by the pandemic.

A police source told AFP that 6,000 police officers had been drafted in to stop any protests -- double the contingency usually placed on reserve.

Key points of China's recently imposed national security law for Hong Kong.
Key points of China's recently imposed national security law for Hong Kong. AFP / John SAEKI

Throughout the morning, groups of prominent democracy activists held small protests -- deliberately keeping to no more than four people.

Four Hong Kong pro-democracy activists march towards the venue of an official ceremony to celebrate China's National Day, chanting slogans such as "End one party rule" while surrounded by some 40 police officers.
Four Hong Kong pro-democracy activists march towards the venue of an official ceremony to celebrate China's National Day, chanting slogans such as "End one party rule" while surrounded by some 40 police officers. AFPTV / Yan ZHAO

"In today's China, those who pursue freedom are suppressed while those doing the suppressing are in power," activist Lee Cheuk-yan told reporters.

One group, surrounded by some 40 police officers, chanted "End one-party rule" and burned a protest petition.

Others gathered outside the heavily guarded Liaison Office that represents Beijing's government in the city.

A day earlier, office director Luo Huining gave a speech calling for more patriotism to be instilled in Hong Kong, saying pride in the motherland was a duty, not a choice.

In Causeway Bay -- a shopping district which saw many clashes last year -- riot police vastly outnumbered residents, shoppers and those chanting slogans on Thursday afternoon.

Officers quickly stopped and searched, or warned to leave, people deemed suspicious -- one man playing a protest song on a whistle, another waving a yellow balloon, the colour associated with the democracy movement.

One protester, who gave only his first name Ricky, said he had chosen to quietly read the pro-democracy Apple Daily newspaper in public.

"Everyone knows that under the national security law you can no longer say many things," he told AFP.

"But I still want to come out, even if it's only a tiny effort I can make."

On the rare occasions when demonstrations have bubbled up, riot police and plain-clothes officers moved quickly -- on one day last month nearly 300 people were arrested.

Over the last 16 months, more than 10,000 have been detained during protests with courts facing a backlog of trials, including of many prominent protest leaders.

The crackdown has been aided by the national security law that China imposed on the city in June.

The broadly worded legislation criminalised expressing certain opinions and allowed mainland China's security apparatus to operate openly in Hong Kong for the first time.

The security law has led to sanctions by the United States and condemnation by many other Western nations.