Scores of demonstrators clashed with riot police last night outside a police station holding protesters charged with rioting after a violent weekend.
Activists were already gathered outside the Kwai Chung Police Station yesterday, calling for those inside to be released.
Tempers flared after police said 44 of those detained would be charged with rioting.
Police used pepper spray and batons to disperse the crowd.
Several hours earlier, tens of thousands of commuters were stranded at a number of train stations during morning rush hour after protesters stopped trains from leaving the platforms.
This was part of a disruptive campaign to show their unhappiness over train operator MTR Corporation's handling of the Yuen Long violence on July 21.
Brutal attacks had broken out that Sunday night at the MTR station in Yuen Long, a suburb near the border with China.