Photo/Illutration Chow Han Tung, vice chairwoman of the Hong Kong Alliance in Support of Patriotic Democratic Movements of China, center, is escorted by police in a van to a court, in Hong Kong on Sept. 10. (AP Photo)

HONG KONG--The group that organized an annual Tiananmen candlelight vigil and three of its leaders have been charged with subversion under Hong Kong’s national security law as authorities intensify the crackdown on dissent in the city.

Tens of thousands of people massed in the city’s Victoria Park for the past 30 years to commemorate China’s bloody military crackdown against pro-democracy demonstrations in Beijing’s Tiananmen Square on June 4, 1989.

It was the only large-scale public commemoration of the crackdown on Chinese soil, featuring crowds of people lighting candles and singing songs to support democracy.

Police have banned the vigils for the past two years citing the coronavirus pandemic, although critics believe the ban is part of the crackdown on dissent Beijing and Hong Kong’s leaders have waged following months of anti-government protests in the territory in 2019.

Authorities have now characterized the Hong Kong Alliance in Support of Patriotic Democratic Movements of China as a foreign agent and sought details about the group’s operations and finances in connection with its alleged activities and links with democracy groups overseas.

Leading members of the alliance have so far refused to cooperate with the police request for information, and five were arrested this week for failing to comply.

The alliance said late Thursday that the group, its chairman, Lee Cheuk-yan, as well as vice-chairs Albert Ho and Chow Hang-tung were charged with inciting subversion of state power under the national security law. The case was brought before court on Friday.

Lee and Ho are already serving jail terms for their roles in unauthorized protests in 2019.

Chow, one of those arrested earlier this week for failing to comply with the police request for information, was denied bail and will be remanded in custody.

Police also Thursday had confiscated computers, documents and promotional materials from the closed June 4 museum, which was run by the alliance to commemorate the Tiananmen crackdown.

Police said 2.2 million Hong Kong dollars ($280,000) worth of assets belonging to the alliance were also frozen.

Over the past year, dozens of pro-democracy activists have been arrested, others have left the city for exile abroad, and the city has amended electoral laws to increase the number of seats for pro-Beijing legislators while reducing those that are directly elected.

The national security law, imposed by Beijing on the city in June last year, criminalizes subversion, secession, terrorism and foreign collusion to interfere in the city’s affairs.

Critics say the national security law, which has been used to arrest more than 100 people, rolls back freedoms promised to the former British colony when it was handed over to China in 1997. Hong Kong had been promised it could maintain freedoms not found on the mainland for 50 years, such as freedom of speech and assembly.