HONG KONG - Reports say Canadian singer and activist Denise Ho is one of at least four people who have been arrested in Hong Kong on suspicion of colluding with foreign forces to endanger China's national security.

The U.K.-based human rights group Hong Kong Watch says Ho was detained by Hong Kong's National Security Police along with Cardinal Joseph Zen, lawyer Margaret Ng and scholar Hui Po-keung.

The group says the arrests are apparently related to their rolesas trustees of the 612 Humanitarian Relief Fund, which provided legal aid to people who took part in 2019 pro-democracy protests that were quashed by security forces.

Scores of pro-democracy activists have been arrested under a sweeping National Security Law imposed on the city by Beijing in 2020. Ho was previously arrested and briefly detained in December. A spokeswoman for the group Alliance Canada Hong Kong says the arrests are a sign of worsening repression in Hong Kong.

Ai-Men Lau is urging the Canadian government to ensure Ho gets proper consular support and to step up humanitarian aid for those impacted by the crackdowns.