Joshua Wong and Agnes Chow, two of the Umbrella Movement's leaders, are still well-regarded among the Hong Kong youth
Joshua Wong and Agnes Chow, two of the Umbrella Movement's leaders, are still well-regarded among the Hong Kong youth AFP / Lillian SUWANRUMPHA

Prominent Hong Kong democracy activists including three lawmakers were arrested Friday in a protest crackdown -- a move described by rights groups as a well-worn tactic deployed by China to suffocate dissent ahead of key political events.

The sweep comes after a major rally planned for Saturday was banned by police on security grounds, and then called off by the organisers.

The latest protest had been due to mark the fifth anniversary of Beijing's rejection of a call for universal suffrage in the semi-autonomous city, sparking the 79-day Umbrella Movement in 2014.

Hong Kong has been locked in three months of political crisis, with increasingly violent clashes between police and protesters that have prompted an escalating intimidation campaign from China.

Two of the Umbrella Movement's leaders, Joshua Wong and Agnes Chow -- both still well-regarded among the city's youth -- were arrested in dawn swoops on Friday and appeared in court accused of "inciting others to take part in unauthorised assembly" among other charges.

After being released on bail they spoke outside the court. Wong vowed to "continue our fight", and railed against the "chilling effect" of the arrests on opponents of Hong Kong's Beijing-backed government.

Authorities are "trying to create white terror" to scare people away from participating in the social and democratic movement, he said -- deploying a term used for China's efforts to fragment and harass the protesters.

The European Union's diplomatic chief Federica Mogherini on Friday said the developments were "extremely worrying".

The day saw rolling arrests of leading pro-democracy voices, including three members of the city's parliament -- Cheng Chung-tai, who advocates greater political autonomy for Hong Kong, Au Nok-hin and Jeremy Tam.

Cheng's arrest was announced by his Civic Passion party, while police confirmed a 35-year-old man surnamed Cheng had been held over "conspiracy to cause criminal damage" linked to the storming of the city's parliament in July.

Police confirmed the late Friday arrests of lawmakers Au and Tam for their roles in "obstructing" officers when riot police cleared protesters from the streets of the densely populated Mong Kok neighbourhood on July 7-8. Au is also accused of assaulting a police officer.

Tam, a long-term pilot for Cathay Pacific, announced on social media last week that after 20 years he was resigning from the airline, which has been accused of bowing to pressure from Beijing.

Leaderless movement

More than 900 people have been arrested in connection with protests since June.

But that has failed to snuff out a leaderless movement, which believes that freedoms in the city, unique within China, are being eviscerated by Beijing.

Pro-democracy campaigner Rick Hui -- a district councillor -- and former student leader Althea Suen were also arrested separately on Friday, while vocal independence campaigner Andy Chan was detained at Hong Kong's airport.

Amnesty International decried the "ludicrous dawn swoops", describing them as "scare tactics straight out of Beijing's playbook".

Police spokesperson John Tse denied the slew of arrests were timed specifically to de-fang the weekend's protests as "totally false".

Hong Kong's crisis-hit government has refused to back down over the protests, which have by turns seen millions march, closed the airport and left city streets strewn with bricks and shrouded in tear gas.

What started as a pushback against a bill allowing extraditions to mainland China quickly morphed into wider calls for democracy and police accountability.

Bonnie Leung of the Civil Human Rights Front (CHRF), the organiser of Saturday's banned rally, said it had "no option but to cancel the march".

However, pockets of protesters have vowed to hold creative events at the scheduled time and place to sidestep the ban.

Those included a mass shopping trip, football match and impromptu religious gatherings in downtown Hong Kong, while a YouTuber with 800,000 followers called a fan meeting.

With a hardcore minority among the protesters, mainly young students, unlikely to heed the police ban, the weekend could be poised for renewed violent clashes.

Student protester Kelly, who wanted to be identified only by her first name, said the arrests would not cow the movement.

"The police think there are leaders behind the protests and this will stop us," she said.

"We are our own leaders and we will keep coming out."

On Sunday, the city saw some of its worst clashes, with running battles between a core group of radical protesters hurling bricks and Molotov cocktails, and police wielding batons, rubber bullets and tear gas.

One officer fired a warning shot -- believed to be the first live round used during the protests -- as a mob with clubs set upon several policemen.

The violence has damaged Hong Kong's reputation for stability and prosperity.