Organisers say 30,000 people took part in a rally in Chater Garden in Central on Wednesday night to protest against alleged police sexual violence towards anti-government protesters, particularly women.
Demonstrators tied purple ribbons on their clothes to show solidarity with the victims.
Organisers say police have been trying to humiliate female protesters to deter them from taking to the streets.
It's been alleged that a female protester was stripped naked during a body search at a police station.
In another incident, video footage showed a female protester partially undressed while she was being carried by officers in Tin Shui Wai earlier this month.
Some people wrote #Protesttoo on their arms with lipstick to show solidarity.
One protester, who gave her name as Elaine, said this was intended to echo the 'Me Too' movement.
"But this time all the victims ... were actually protesters. So we were actually trying to make a hashtag - Protest Too, echoing Me Too," she said.
Another protester said she couldn't believe the police denials in the face of the video clips showing the partially undressed protester.
The rally ended peacefully, with protesters chanting: "Hongkongers, see you in Chater Garden on August 31,” - a reference to a protest being organised by the Civil Human Rights Front.
Last updated: 2019-08-28 HKT 22:30