Pro-democracy protesters in Hong Kong clashed with police as anti-government demonstrators took to the streets for the 24th weekend in a row.
Black-clad activists smashed up commercial premises as police responded with batons.
The latest violence comes two weeks before district council elections in the Chinese-ruled city.
The clashes spilled on to the streets outside the V City mall with running battles between police and demonstrators.
Pro-democracy protesters vandalised a train station in the central new town of Sha Tin and smashed up a restaurant perceived as being pro-Beijing, overturning banqueting tables and smashing glass panels
As darkness fell, the violence spread.
Call for revenge
The latest violence followed a gathering of thousands of people at a vigil on Saturday night for a student who died in hospital this week following a high fall during a protest.
Many called for revenge.
Seven pro-democracy city lawmakers have been detained or face arrest and are due to appear in court on Monday on charges of obstructing a May meeting of the local assembly, according to police and several of the lawmakers.
Protesters are angry about what they see as police brutality.
They are also angry about claims that Beijing is meddling in the former British colony's freedoms, guaranteed by the "one country, two systems" formula in place since the territory returned to Chinese rule in 1997.
China denies interfering and has blamed Western countries for stirring up trouble.