Hong Kong police have thrown tear gas canisters at protesters after they refused to disperse.
Hundreds of thousands of people took part in a march Sunday to call for direct elections and an independent investigation into police tactics used during earlier pro-democracy demonstrations.
Police waved a black warning flag Sunday night before lobbing the canisters into a crowd of protesters.
Protesters had earlier defaced the Chinese national emblem on the building of the Liaison Office, which represents mainland Chinese authorities in the city.
Hong Kong is a Chinese territory that has been promised certain freedoms under a "one country, two systems" framework. Massive protests began last month against an extradition bill that would have allowed Hong Kong residents to be sent to the mainland to stand trial.
A blackened national Chinese emblem has become Hong Kong residents' latest expression of protest against mainland authorities after tens of thousands of people took part in the city's latest pro-democracy march.
After the march reached its designated end point in Wan Chai district on Sunday, thousands continued onwards, at various points occupying key government and business districts before departing for the Liaison Office, which represents China's Communist Party-led central government within the city.
Protesters threw eggs at the building and spray-painted its surrounding surveillance cameras. China's national emblem, which adorns the front of the Liaison Office, was splattered with black ink.
Massive pro-democracy protests began last month in opposition to a contentious extradition bill that would have allowed Hong Kong residents to stand trial in mainland China.
Tens of thousands of Hong Kong protesters have kicked off a march from a public park to call for an independent investigation into police tactics.
Marching under sweltering heat, protesters dressed in black walked Sunday behind a large banner reading "Independent Inquiry for Rule of Law."
Massive pro-democracy protests began last month in opposition to a contentious extradition bill that would have allowed Hong Kong residents to stand trial in mainland China, where critics say their rights would be compromised.
The city's leader has declared the bill dead, but some protesters are also calling for her to resign amid growing concerns about the steady erosion of civil rights in the Chinese territory.
The demonstrations have since ballooned into calls for democratic reforms and an investigation into alleged police brutality.
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