Protesters sit in front of the Legislative Council building during a demonstration in Hong Kong on Sunday. Thomas Peter / Reuters

Hundreds of thousands of protesters choked Hong Kong's streets for a second straight Sunday in a defiant rebuke of a reviled extradition law, piling pressure on the city's embattled pro-Beijing leader despite a weekend climbdown.

The show of force saw huge crowds marching for hours in tropical heat, calling for the resignation of chief executive Carrie Lam, who paused work on the divisive bill Saturday saying she had misjudged the public mood.

Throngs of black-clad protesters snaked their way for miles through the city's streets to the city's parliament − a repeat of a record-breaking demonstration last Sunday that organisers said more than a million people attended.

As night fell the huge crowds were still marching, but they had also taken over multiple major thoroughfares, with the police seemingly ceding the streets to the jubilant masses.

Critics fear the Beijing-backed law will entangle people in China's notoriously opaque and politicised courts and damage the city's reputation as a safe business hub.

Although Lam offered a rare concession on Saturday, she stopped short of committing to permanently scrapping the unpopular law.

Her gesture was swiftly rejected by protest leaders who called on her to resign, shelve the bill entirely and apologise for police using tear gas and rubber bullets earlier in the week.

"The pro-democracy group will not stop at this point, they want to build on the momentum against Carrie Lam," political analyst Willy Lam told AFP. "They will keep the heat on and ride the momentum." - Anger at police - The international finance hub was rocked Wednesday by the worst political violence in decades as tens of thousands of protesters were dispersed by baton-wielding riot police.

Many placards in the crowd Sunday accused police of using excessive force.

"You're supposed to protect us not shoot at us," read one banner.

Nearly 80 people were injured in this week's unrest, including 22 police officers, with both sides showing a willingness to escalate their behaviour to levels unseen before in the usually stable business hub.

One man died late Saturday when he fell from a building where he had been holding an hours-long anti-extradition protest.

He had unfurled a banner on scaffolding attached to an upscale mall, but fell when rescuers tried to haul him in. Police said they suspected the 35-year-old man was suicidal.

Throughout the day, demonstrators queued for hours to leave flowers and tributes where he fell.

The extradition furore is just the latest chapter in what many see as a battle for the soul of Hong Kong.

Restore calm to the community

For the last decade the city has been convulsed by political turbulence between the pro-Beijing authorities and opponents who fear an increasingly assertive China is stamping on the city's unique freedoms and culture enjoyed since the handover in 1997.

Opposition to the extradition bill has united an unusually wide cross-section of Hong Kong from influential legal and business bodies to religious leaders.

Lam's decision to ignore those warnings, and press ahead with the bill even after last weekend's massive rally, has placed her administration under pressure from both her opponents and her own allies.

Advisers and pro-establishment lawmakers urged her to delay the bill after Wednesday's violence, while Beijing began to distance itself from her administration.

Her climbdown was also a rare example of the city's unelected leaders caving-in to demonstrations − something more recent administrations have been increasingly unwilling to do.

Two months of protests in 2014 calling for the right to directly Hong Kong's leader won no concessions from Beijing, and key figures from that movement are now in jail.

Keep the heat on

Estimates of Sunday's crowd size will not be available until later Sunday, but the last marchers to leave the rally's starting point at a public park left some six hours after it started.

Earlier in the day, activists hung a huge banner from Lion Rock mountain that read "Defend Hong Kong".

"Personally I think she can no longer govern Hong Kong, she has lost the public," Dave Wong, a 38-year-old protester who works in finance, told AFP.

"She has pretended not to hear or see our troubles or the injured protesters, and even called them rioters − this makes us Hong Kong residents furious," added demonstrator Calvin Wong.

In mainland China, the internet was scrubbed clean of references to the massive rally, with entries for Hong Kong on search engines and social media platforms showing no sign of the demonstration.

Police said they had no choice but to use force to meet violent protesters who besieged their lines outside the city's parliament on Wednesday.

But critics − including legal and rights groups − say officers used the actions of a tiny group of violent protesters as an excuse to unleash a sweeping crackdown on the predominantly young, peaceful protesters.

Agence France-Presse