Hong Kong police fired tear gas and arrested a number of people on Sunday as they tried to disperse protesters calling for electoral reforms and a boycott of the Chinese Communist Party.
Thousands of demonstrators had packed into Chater Garden, not far from the Chinese territory's Legislative Council building for the march.
But while the protest began peacefully, it increasingly descended into violence after demonstrators flowed out of the garden and moved into nearby streets, where they were joined by others.
Protesters used bricks, umbrellas and traffic barriers to barricade a road.
They then ran for cover after riot police appeared and raised yellow warning flags, telling demonstrators that they should disperse because they were participating in an illegal assembly.
Speaking to Euronews' Good Morning Europe, pro-democracy activist Wilson Leung, said the unrest occurred in part because of heavy-handed police tactics.
"The problem is the police created a very intense situation in the first place," he said.
"It was very peaceful inside the venue but then suddenly the police grabbed the mic and announced that the rally had to end. This caused quite a lot of unhappiness amongst the protesters," he said.
You can watch the full interview in the player above