What started off as a peaceful demonstration, ended up in clashes between riot police and protesters on Wednesday afternoon.
Thousands of demonstrators surrounded Hong Kong's government headquarters to show their opposition to a new extradition bill that will allow suspects to be sent to mainland China for trial.
The demonstrators fear the bill would allow Chinese authorities to take people for political reasons and undermine Hong Kong's semi-autonomous legal system.
"Today the Hong Kong people want to tell the Hong Kong government that on the ninth of June, we had more than one million people coming out on the street, and we can't give up simply because the government ignored our demand, because this is our home.
"We only want to paralyze the legislative council, so please don't rush in, don't get beaten and don't let others make excuses for you, ok?"
Protesters blocked access to the area with barricades and when they refused to back down, riot police started using force to push them back.
Police were seen using batons, rubber bullets, and tear gas on demonstrators who were seen throwing water bottles and rocks at police.
It was some of the worst violence in Hong Kong since the territory was handed back to China by the British in 1997.
At least 72 people were injured, with two injuries classed as serious, according to the Hong Kong Hospital Authority.
The scenes brought back memories of the Umbrella Movement democratic protests of 2014.
Despite the outpouring of opposition, Hong Kong Chief Executive Carrie Lam looks set to plow ahead with the bill.
"I will not shy away from my responsibility in introducing a piece of legislation - though we are very convinced of the justifications - that's causing this public outcry and all this divisiveness in society. But sometimes, as a political leader you cannot shy away from difficult decisions."
The extradition law is likely to pass because the city's 70-seat Legislative Council is controlled by a pro-Beijing majority.
Hong Yoo, Arirang News.