Hong Kong police arrested 53 former lawmakers and activists on Wednesday. Authorities accused them of breaching a new national security law by participating in unofficial election primaries for the territory's legislature last year. The mass arrests were the largest since the law was imposed by Beijing last June. “The operation today targets the active elements who are suspected to be involved in the crime of overthrowing, or interfering [and] seriously destroy the Hong Kong government’s legal execution of duties,” said John Lee, Hong Kong’s security minister, in a news conference. He said those arrested were suspected of trying to paralyse the government, via their plans to gain a majority of the seats in the legislature, to create a situation in which the chief executive had to resign and the government would stop functioning. In a video released by former lawmaker Lam Cheuk-ting on his Facebook page, police turned up at his house and told him he was “suspected of violating the national security law, subverting state power.” The legislative election that would have followed the unofficial primaries was postponed by a year, by Hong Kong Chief Executive Carrie Lam, who cited public health risks during the coronavirus pandemic. Mr Lee said the police would not target those who had voted in the unofficial primaries, which were held in July last year and attracted more than 600,000 voters, even though pro-Beijing lawmakers and politicians had warned the event could breach the security law. All of the pro-democracy candidates in the unofficial primaries were arrested, according to tallies of the arrests being reported by the South China Morning Post, online platform Now News and political groups. At least seven members of Hong Kong’s Democratic Party — the city’s largest opposition party — were arrested, including former party chairman Wu Chi-wai. Benny Tai, a key figure in Hong Kong’s 2014 Occupy Central protests and a former law professor, was also arrested, reports said. Mr Tai was one of the main organisers of the primaries. The home of Joshua Wong, a prominent pro-democracy activist who is serving a 13 1/2-month prison sentence for organising and participating in an unauthorised protest last year, was also raided, according to a tweet posted from Wong’s account. American human rights lawyer John Clancey was also arrested on Wednesday. Mr Clancey was the treasurer of political group Power for Democracy, which was involved in the unofficial primaries. Police also went to the headquarters of Stand News, a prominent pro-democracy online news site in Hong Kong, with a court order to hand over documents to assist in an investigation related to the national security law, according to a live streamed video by Stand News. No arrests were made. In recent months, Hong Kong has jailed several activists including Wong and Agnes Chow for their involvement in antigovernment protests, and others have been charged under the national security law including media tycoon and outspoken pro-democracy activist Jimmy Lai. The security law criminalises acts of subversion, secession, terrorism and collusion with foreign powers to intervene in the city’s affairs. Serious offenders could face up a maximum punishment of life imprisonment. Hong Kong leader Carrie Lam had said at the time of the unofficial primaries last year that, if their aim was resisting every policy initiative by the Hong Kong government, the election may fall under subverting state power, an offence under the national security law. Beijing had also called the primaries illegal and a “serious provocation” of Hong Kong’s electoral system. Following the handover of Hong Kong to China by the British in 1997, the semi-autonomous Chinese city has operated on a “one country, two systems” framework that affords it freedoms not found on the mainland. In recent years, Beijing has asserted more control over the city, drawing criticism that it was breaking its promise of Hong Kong maintaining separate civil rights and political systems for 50 years from the handover. The sweeping arrests drew condemnation from Anthony Blinken, tapped to be US secretary of state by the incoming Biden administration.