Activists in Hong Kong have desecrated a Chinese flag and vandalised a shopping centre on the 16th straight weekend of anti-government protests.
Escalators and glass panels were targeted at the New Town Plaza in Sha Tin. Police have closed it and fired tear gas at brick-throwing protesters.
Police earlier prevented major unrest on the airport metro system.
The protests were sparked by a now-withdrawn extradition bill but morphed into a wider pro-democracy campaign.
Issues such as universal suffrage, a demand for an inquiry into police actions and the alleged involvement of gangs in countering the protests have come to the fore.
The campaign, mostly conducted by young people, was peaceful to start with but has become increasingly violent.
The unrest has become the biggest challenge to China's rule since Hong Kong's sovereignty was handed back by Britain in 1997.
Hong Kong is part of China, but enjoys "special freedoms". Those are set to expire in 2047, and many in Hong Kong don't want to become "another Chinese city".
What happened on Sunday?
The unsanctioned rally at the New Town Plaza started on a small scale and peacefully.
Video footage then showed a Chinese flag being trampled by protesters before being carried out and thrown into a river.
Masked protesters used fire extinguishers to smash the glass of information maps, then sprayed water and threw rubbish bins down escalators. Pro-mainland businesses were reportedly targeted.
Riot police closed down the mall and the linked metro station in Sha Tin, a city in the New Territories north of Hong Kong Island.
Outside, protesters started ripping up pavement bricks and throwing them at police, who fired tear gas in response.
A barricade was set on fire elsewhere in Sha Tin.
The luxury Elements shopping centre in Kowloon was also closed as police and protesters squared off, the South China Morning Post reported.
What of the airport protest?
Protester groups online had called for a "stress test" of the airport on Sunday. The airport has become one of the high-profile targets of protesters.
But police stepped up security and authorities reduced transport links to head off possible unrest.
The Airport Express metro link was open only to passengers boarding at Hong Kong island.
Only people with flight tickets could board.
What's the background?
Protests began in June in opposition to a proposed bill that would have made it possible for people in Hong Kong to be extradited to mainland China.
Critics said they could have faced human rights abuses.
The bill was initially shelved, and later withdrawn completely, but this has failed to quell the protesters' anger.
Their demands have been rejected by both Beijing and Hong Kong's Chief Executive Carrie Lam, who on Sunday again vowed to stop the violence.
BDST: 1847 HRS, SEP 22, 2019