Riot police fired tear gas, water cannon, and pepper spray after thousands of protesters surrounded the legislature and forced a delay in a debate over a controversial extradition bill.
What was a relatively peaceful demonstration erupted on Wednesday afternoon at about 3.30pm local time (07:00GMT) as hundreds of protesters tried to storm the legislative council complex, prompting police to retaliate.
Black-shirted protesters wearing helmets and goggles taunted police outside the Legislative Council (Legco) on Wednesday, as they descended on the streets against the bill which, critics say, will undermine the city's civil freedoms.
The front line of demonstrators in hard hats and goggles, their faces covered with masks, moved metal crowd control barriers, ignoring police pleas to stop. After several failed attempts, the crowd gained access to the grounds of the building and the police released more tear gas to push them back.