(May 28): Hong Kong’s national security police arrested six people using a new security law for the first time, days ahead of the 35th anniversary of the Tiananmen Square crackdown.

Police said a woman under detention made social media posts with seditious intent with the help of five others, according to a government statement Tuesday. The postings incited people to join unlawful acts close to a “sensitive date”, according to the announcement, which didn’t identify the occasion.

They were suspected of violating the new Safeguarding National Security Ordinance. The offence carries a maximum penalty of seven years of imprisonment. The arrests were made about two months after officials fast-tracked the legislation and prompted overseas warnings it could muzzle free speech in the city.

Security chief Chris Tang identified the woman as Chow Hang-tung, former vice chairperson of a Hong Kong activist group that organized an annual vigil to commemorate Beijing’s bloody suppression of pro-democracy protesters in the Chinese capital in 1989. She had been under detention for a separate charge and was arrested at Tai Lam Centre for Women, a maximum security institution.

“The suspects incited hatred and distrust of the central government, the Hong Kong government and the judiciary,” Tang told reporters at a briefing. “We must take resolute action to protect the security of Hong Kong and our country.”

Chow’s group, the Hong Kong Alliance in Support of Patriotic Democratic Movements of China, was dissolved in 2021 as it came under pressure of a national security law imposed by Beijing the year before.

The Asia finance hub passed its own, domestic security legislation in March to further protect the Chinese state.

The new law’s broadly defined state secrets offences bring Hong Kong in line with China’s vague espionage legislation, which has spooked foreign investors over the past year. New crimes such as treason and insurrection carry life sentences, expanding authorities’ toolkit to crush political opposition, a drive that’s hurt the city’s ties with some Western democracies.