The US has called for the release of 30 leaders of one of China's largest underground church networks who were reportedly detained over the weekend in overnight raids across various cities.

The list includes several pastors and Zion Church founder Jin Mingri, who was arrested in the early hours of Saturday after 10 officers searched his home, according to US-based non-profit ChinaAid.

The Chinese Communist Party promotes atheism and tightly controls religion, yet some Christian groups are claiming this is the most extensive crackdown against the faith in decades.

Christians have long been pressured to join only state-sanctioned churches led by government-approved pastors who adhere to the party line.

It remains unclear if the detainees have been formally charged.

Zion Church released a statement calling the systematic persecution not only an affront to their faith but also a public challenge to the international community. US Secretary of State Marco Rubio emphasized that the crackdown underscores the CCP's hostility towards Christians who reject state interference in their worship.

Prominent figures such as former US vice-president Mike Pence and former secretary of state Mike Pompeo have also condemned the arrests.

At a press conference, Chinese foreign ministry spokesperson Lin Jian claimed ignorance about the case, asserting that the Chinese government governs religious affairs in accordance with the law and defends the religious freedom of its citizens.

This incident may further complicate the increasingly strained US-China relationship, already marked by trade tensions over tariffs and export controls.

Under Xi Jinping's leadership, Beijing has tightened its grip on religious freedoms, especially targeting Christians and Muslims. Despite this, there has been a noticeable rise in unregistered house churches, including Zion Church, which was founded by Jin in 2007 and has grown into one of China's largest underground congregations.

ChinaAid characterized the recent detentions as an unprecedented and coordinated wave of persecution against Christians, reminiscent of some of the darkest days in China's religious history.

In a heartfelt message, Jin Mingri's wife expressed her shock and sorrow, insisting that her husband is innocent. Sean Long, a pastor affiliated with Zion Church, revealed that Jin had anticipated such a crackdown.

Despite these persecutions, the church has continued to gather in small groups and share sermons online, embodying resilience against adversity.