Saturday's rally comes a day ahead of yet another mass protest planned against the government and its handling of the now-suspended extradition bill that would have allowed people in Hong Kong to be sent to mainland China for trial.

Hong Kong's embattled leader, Carrie Lam, has apologised for the turmoil the bill has caused and declared it "dead", although opponents seek full withdrawal.

Demonstrators, mostly middle-aged or older, braved heavy rain to gather at the city's Tamar Park, next to the Legislative Council which protesters stormed and raided on July 1 - the 22nd anniversary of handover to Chinese rule.

"Violence is intolerant. We are distressed about our home and we should absolutely stand out to support Hong Kong police, to maintain stability and rule of law in the society," Tsol Pui, 85, president of Hong Kong Veterans' Home, said.

Two protests last weekend degenerated into running skirmishes between baton-wielding riot police and activists, resulting in injuries and more than 40 arrests.

The fights followed larger outbreaks of violence between police and protesters in central Hong Kong last month, with police forcing back activists with tear gas, rubber bullets and bean-bag rounds.

What started as protests over the extradition bill has now morphed into demands for greater democracy, the resignation of leader Lam and curbing the number of mainland Chinese tourists to Hong Kong.

Under the terms of the handover from Britain in 1997, Hong Kong was allowed to retain extensive freedoms not enjoyed on the mainland under a "one country, two systems" formula, including an independent judiciary and right to protest.

But for many Hong Kong residents, the extradition bill is the latest step in a relentless march toward mainland control.

Australian Associated Press