Police used pepper spray and tear gas on anti-government protesters in Tsim Sha Tsui on Sunday afternoon as they spilled over onto the roads.
Tens of thousands of people gathered at the clock tower to march to the Hong Kong Coliseum in Hung Hom, with some occupying all lanes on Salisbury Road.
Riot police unfurled a blue flag warning people to get back on the pavement, and then used pepper spray to disperse protesters blocking the road.
Later officers charged at groups of protesters and fired tear gas. Some people were seen throwing objects in retaliation. At least two people were held down and subdued by police.
At one point officers warned people walking through the public area in Salisbury Garden that they were taking part in an illegal assembly and told them to move on.
The march, branded "Never Forget" on social media, is to remind people the fight isn't yet over despite a landslide victory by the pro-democracy camp in last Sunday's district council elections.
The protesters, clad in black and wearing face masks, chanted “five demands, not one less” and other slogans.
One of them, a university student, said they won’t give up: "It's very important for the people to tell the government that we haven't given up. So this is our demands; five demands not one less."
He said they won't stop until the government has answered all five demands which include an independent investigation into allegations of police brutality, an amnesty for all those arrested and genuine universal suffrage.
Another protester said he didn’t understand why police would object to an investigation, as Hong Kong is a city that embraces rule of law.
He added that march was useful to remind people of what the movement is about following the previous Sunday's district council vote.
By around 6.30pm most of the protesters and police had dispersed.
Last updated: 2019-12-01 HKT 18:30