Police used pepper spray during a "silent protest" on Sunday against the national security law.
Officers targeted protesters outside the popular mall, CTMA Centre, in Mong Kok, forcing shops to pull down shutters, nearly two hours after the protest began in Jordan.
Witnesses said police took action after an officer fell to the ground while trying to disperse the crowd. A number of people, including journalists, received treatment at the scene.
The rally began at around 3 in the afternoon. Some in the crowd chanted pro-independence protest slogans.
They also called on people to go to Victoria Park on Wednesday, the 23rd anniversary of the handover.
The Civil Human Rights Front is appealing against a police ban on a proposed march, with the force citing social distancing and a threat to public order to prohibit the annual July 1 march for the first time ever.
In Jordan, some of the crowd reminded others that it was a silent event, saying they should keep a low profile and refrain from chanting.
Some demonstrators then put up hand gestures signalling the anti-government protests' "five demands, not one less" mantra.
Officers used loudhailers asking people not to stop and gather, saying they would otherwise be taking part in an unauthorised rally.
Police also stopped and searched a number of people in the area, before letting them go.
Officers also handcuffed a man on Hamilton Street and took him away.
Last updated: 2020-06-28 HKT 17:23
Pepper spray used in protest against security law
2020-06-28 HKT 15:42
2020-07-04 HKT 17:05
2020-07-04 HKT 13:02
2020-07-04 HKT 10:24
2020-07-04 HKT 09:40
2020-07-04 HKT 09:11
2020-07-04 HKT 00:23
2020-07-03 HKT 16:44
2020-07-03 HKT 15:31
2020-07-03 HKT 15:28
2020-07-03 HKT 13:42
2020-07-03 HKT 13:01
2020-07-03 HKT 12:47
2020-07-03 HKT 12:28
2020-07-03 HKT 11:58