Cardinal Joseph Zen, the retired Bishop of Hong Kong, has been arrested by China’s security police.

The 90-year-old cardinal was taken into custody along with three others; all of those arrested were involved with the 612 Humanitarian Relief Fund, which was set up to provide legal defense for pro-democracy activists. The Chinese government has charged that the group undermines the Hong Kong government.

Cardinal Zen has long been a critic of the Beijing regime, pointing to multiple violations of religious freedom. The sweeping “national security” law enacted in Hong Kong in 2020 inaugurated an aggressive campaign against all political dissent.

While the White House immediately called for the release of the cardinal and his associates, saying that they were “unjustly arrested and charged,” the Holy See offered a muted response. Press spokesman Matteo Bruni said that the Vatican is “following the evolution of the situation with extreme attention.”

The Chinese prelate has frequently warned that Vatican efforts to reach a diplomatic accord with Beijing have heightened the danger to the freedom of the Church.