Tens of thousands of protesters gathered in Hong Kong’s Victoria Park and surrounding streets for an “extremely peaceful” anti-government rally.
A couple of underground stations were closed to prevent overcrowding because so many people were arriving.
Many of them wore black and carried umbrellas, which have become a symbol of the protests.
Drenched by heavy rain, they chanted “cheer for Hong Kong” and “free Hong Kong”.
Medical tents were set up amid concerns about potential violence.
Goggles and masks were handed out, as well as saline solution, to counter the effects of tear gas.
Sky News correspondent Diana Magnay, who is there, said it had been “extremely peaceful” and an “extremely powerful message of support for democracy”.
She added that it was a “very strong indication of how much popular support there still is for the protest movement”.
Kiki Ma, a 28-year-old accountant taking part in the protest, said peace was the “number one priority today”, adding: “We want to show that we aren’t like the government.”
Activist Joshua Wong told Sky News that half a million people could turn up and that it was a battle of “David versus Goliath”.
With Beijing moving troops to the border, he said he hoped that China’s President Xi would realise that potentially sending troops into Hong Kong was “not the way out”.
“People really worry about the next Tiananmen Square massacre,” he added.
The protesters are fighting for the “fundamental right” to elect their own government, he said.
The demonstration was led by the Civil Human Rights Front, which organised marches in June that attracted a million people.
Organiser Bonnie Leung said the police would be to blame if chaos ensued.
She added that it was a “day of peace” and that “we hope we can show the world that Hong Kong people can be totally peaceful”.
There was a brief stand-off on Saturday night between police and protesters outside a police station in the Mong Kok district. No tear gas was used but officers said they fired one baton round.
Initially, the demonstrations were over a now-suspended bill that would allow criminal suspects in Hong Kong to be extradited to mainland China.
But broader concerns about the erosion of freedoms under the “one country, two systems” formula – enacted after Britain handed Hong Kong back to China in 1997 – are now part of a series of concerns.
The protesters want democratic reforms and the city’s Beijing-backed leader, Carrie Lam, to resign.