Police in Hong Kong arrested 53 people during protests last night that saw hundreds of activists take to the streets, before police fired pepper-spray to disperse crowds.

The protests, called to mark a year of pro-democracy rallies, also came amid heightened tensions due to a proposed national security bill backed by the central government in Beijing.

Protesters had defied a ban on gatherings of more than eight people introduced by the Hong Kong government to prevent the spread of the coronavirus.

More protests are planned in coming days, with pro-democracy supporters fearing the proposed national security legislation will dramatically stifle freedoms in the city.

While details of the security law or how it will operate have yet to be revealed, authorities in Beijing and Hong Kong have said there is no cause for concern and the legislation will target a minority of "troublemakers".

Hong Kong Security Secretary John Lee told the South China Morning Post in an interview published today that local police were setting up a dedicated unit to enforce the law and it would have intelligence gathering, investigation and training capabilities.

Companies including HSBC and Standard Chartered have backed the security law without knowing the details of it, drawing criticism from some investors and US and British officials.

US Secretary of State Mike Pompeo singled out HSBC yesterday, saying such "corporate kowtows" got little in return from Beijing and criticising the Chinese Communist Party's "coercive bullying tactics".

Hong Kong's year of pro-democracy protests was sparked by a government bill that would have allowed people to be extradited to mainland China, where courts are controlled by the Communist Party, for trial.

Hong Kong leader Carrie Lam withdrew that bill as the rolling protests gathered pace.