Hong Kong police on Tuesday detained two men on suspicion of violating the city’s national security law through links with a now-defunct fund that aimed to help people arrested in the pro-democracy protests in 2019, according to AP News.

The two men were suspected of conspiring to collude with the 612 Humanitarian Relief Fund to receive overseas donations and provide financial support to people who fled Hong Kong or organizations that called for sanctions against the city, police said in a statement. They did not identify the suspects or those alleged to have been aided by them.

The arrests were widely seen as part of a crackdown on dissidents launched by the Hong Kong government following the massive protests. More than 260 people have been arrested under the Beijing-imposed security law, including many of the city’s most prominent activists.

Last year, the fund’s former trustees, including Roman Catholic Cardinal Joseph Zen and singer Denise Ho, were also arrested under the tough law. Zen’s arrest sent shockwaves through the Catholic community.

The ex-trustees have not yet been charged with national security-related crimes, but they were fined in a separate case in November for failing to register the fund, which ceased operation in 2021.

Earlier this month, police also arrested 10 others whom they accused of endangering national security through their alleged involvement with the fund. They included activists Bobo Yip and Cheuk Kai-kai, who campaigned against the government’s development plans years ago, according to local media reports.

Police said the pair arrested on Tuesday were suspected of conspiracy to collude with foreign forces to endanger national security and inciting others to commit riots. Officers searched their homes and the residence of another suspect with court warrants, they said. Some computers and electronic communication devices were seized.

The operation was ongoing and police did not rule out further arrests, they added.

The 2019 protests were sparked by a since-withdrawn bill that would have allowed criminal suspects to be extradited to mainland China. Critics worried the suspects would disappear into China’s opaque and frequently abusive legal system. Opposition morphed into months of violent unrest in the city.