Hong Kong's businesses and metro stations reopened as usual on Monday after a chaotic Sunday when police fired water cannon, tear gas and rubber bullets at protesters who blocked roads and threw petrol bombs outside government headquarters, Euronews reports.

On Sunday what began as a mostly peaceful protest earlier in the day spiraled into violence in some of the Chinese territory's busiest shopping and tourist districts.

Thousands of anti-government protesters, many clad in black masks, caps and shades to obscure their identity, raced through the streets, engaging in cat-and-mouse tactics with police, setting street fires and blocking roads in the heart of Hong Kong where many key business districts are located.

The demonstrations are the latest in nearly four months of sometimes violent protests. Protesters are furious over what they see as creeping interference by Beijing in Hong Kong's affairs despite promises by Beijing to grant the city wide-ranging autonomy and freedoms denied in mainland China.

Dozens of university students rallied peacefully on Monday afternoon urging authorities to listen to public demands. Dressed in black, some of them donning face masks, students sang "Glory to Hong Kong" a song that has become a rallying cry for more democratic freedoms in the semi-autonomous Chinese hub.

At Baptist University hundreds of students also marched to demand the university's management offer support to a student reporter arrested on Sunday.

The initial trigger for the protests was a contentious extradition bill, now withdrawn, that would have allowed people to be sent from Hong Kong to mainland China for trial.

The protests have since broadened into other demands including universal suffrage and an independent inquiry into allegations of excessive force by the police.

Hong Kong, a former British colony, returned to China in 1997 under a "one country, two systems" formula that guarantees freedoms not enjoyed on the mainland - including a much-cherished independent legal system.