Protesters that had stormed Hong Kong parliament were dispersed after police fired tear gas to deal with the situation.
Activists had occupied the Legislative Council (LegCo) building for hours after breaking away from a protest on the anniversary of Hong Kong’s transfer of sovereignty to China from Britain.
Later, hundreds of police charged towards the building after warning protesters to clear it.
The chaos follows weeks of unrest in the city over a controversial extradition law.
Hundreds of thousands took part in the earlier protest against a proposed law that critics fear could be used to extradite political dissidents to mainland China.
The protesters stormed into Parliament through the glass facade of LegCo and were joined inside by hundreds more after police vacated the building during the evening.
Inside, they defaced the emblem of Hong Kong in the central chamber, raised the old British colonial flag, spray-painted messages across the walls, and shattered furniture.
Protesters clad in plastic helmets and brandishing umbrellas retreated from a baton charge by riot police, who quickly overcame the makeshift barriers in front of the building.
Inside, diehard protesters were pulled forcibly outside by their fellow occupants in an attempt to completely clear the building.