The United States has condemned last year, saying the police action jeopardises a high degree of autonomy guaranteed the southern Chinese city.
Among those arrested on Saturday were 81-year-old activist and former lawmaker Martin Lee and democracy advocates Albert Ho, Lee Cheuk-yan and Au Nok-hin.
Police also arrested media tycoon Jimmy Lai, who founded the local newspaper Apple Daily.
Former lawmaker and pro-democracy activist Martin Lee talks to the media as he leaves the Central District police station in Hong Kong. Source: AFP
The sweeping crackdown amid the coronavirus pandemic is based on charges of unlawful assembly stemming from huge rallies against proposed China extradition legislation that exposed deep divisions between democracy-minded Hong Kongers and the Communist Party-ruled central government in Beijing.
, but the protests continued for more than seven months, centred around demands for voting rights and an independent inquiry into police conduct.
While the protests began peacefully, they increasingly descended into violence after demonstrators became frustrated with the government's response.
They feel that Hong Kong leader Carrie Lam had ignored their demands and used the police to suppress them.
US Secretary of State Mike Pompeo condemned yesterday's arrests in a statement.
"Beijing and its representatives in Hong Kong continue to take actions inconsistent with commitments made under the Sino-British Joint Declaration that include transparency, the rule of law, and guarantees that Hong Kong will continue to 'enjoy a high degree of autonomy,'" Mr Pompeo said.
He was referring to the 1997 handover of the former British colony to China, which promised the city would enjoy political freedoms not afforded mainland China.
Britain's Foreign Office also criticised the arrests, saying "the right to peaceful protest is fundamental to Hong Kong's way of life and as such is protected in both the Joint Declaration and the Basic Law".
Beijing has accused the US and other western countries of instigating the protests and insists they are China's internal affairs.
Hong Kong riot police officers in formation during the New Years Day pro-democracy demonstration. Source: LightRocket
The Office of the Commissioner of the Chinese Foreign Ministry in Hong Kong said police were enforcing the law against those suspected of organising and participating in unauthorised assemblies, and foreign countries have no right to interfere, China's official Xinhua News Agency reported.
