Flashmob protests and vandalism broke out in multiple locations, prompting riot police to use pepper spray and make arrests in at least two shopping centres as members of the public heckled the officers.
AFP reporters in a Sha Tin mall saw a secondary school girl and a 16-year-old boy arrested, the pair shouting out their details as officers led them away.
Earlier in the afternoon an elderly woman was knocked over in the same mall after a fight broke out when a shopper tried to stop protesters from spraying graffiti.
Masked activists had also trashed restaurants run by Maxim’s, a catering giant owned by a tycoon that has become a frequent target because his daughter has criticised the pro-democracy movement.
The skirmishes are the first to break out in three weeks.
Hong Kong has been upended by six months of massive pro-democracy protests that have seen violent battles between police and hardcore demonstrators, as well as regular transport disruption.
The past month had seen a lull in the violence and vandalism after pro-democracy parties won a landslide in local council elections.
Last Sunday an estimated 800,000 marched peacefully through the streets.
But public anger remains as Beijing and city leader Carrie Lam show no sign of giving further concessions despite the election success.
Lam is currently in Beijing for an annual visit and is set to meet President Xi Jinping on Monday.
The protests were ignited by a now scrapped plan to allow extraditions to the authoritarian mainland but have since morphed into a revolt against Chinese rule.
Among the movement’s demands is an independent inquiry into the police and fully free elections.
In a separate protest, around 1,000 people waving Chinese flags rallied in a park on Sunday afternoon in support of the city’s police force.
Coupled with the trade war, the protests have hammered the economy and helped tip the city into recession as tourists stay way.
Hong Kong’s airport on Sunday reported its steepest drop in passengers in a decade — down 16 percent in November compared to the same month the year before.
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