An influential house church in Beijing was shut down Saturday after 20 government and police officials raided Bible classes at two different locations, changed the locks and demanded congregants vow never to worship as a congregation again.

China’s crackdown against underground house churches continued last Saturday with the forced closure of Beijing’s Shouwang Church.

Shouwang Church is one of the most prominent among thousands of unregistered house churches in the city and is said to be attended by over 1,000 people.

As the congregation has suffered through years of challenges and persecution at the hands of the government for refusing to join the state-sanctioned church, it was accused of refusing to register with the government as a “social organization.”

But according to the nonprofit run by prominent Chinese human rights leader Bob Fu, the church had previously submitted an application to the Haidian District Ethnic and Religious Affairs Bureau in 2006 but was rejected because founding Pastor Jin Tianming was not officially ordained by the state.

Christians attending the Bible classes had planned to meet around 1 p.m. but instead were taken by policy to a nearby school where they were held for hours, questioned and told that the church had been shut down.

The nonprofit NGO International Christian Concern reports that another group of Christians affiliated with the church were detained from another location and also taken to the school. Officials reportedly switched out the locks at both locations of the raids.

The number of Christians detained by police for hours before being released is believed to be between 20 and 30, reports.

According to ICC, officials read out a document formally banning Shouwang Church and demanded that those in attendance sign a letter vowing that they will no longer attend the church. However, the detainees reportedly refused.

Additionally, authorities were said to have demanded that Pastor Zhang Xiaofeng sign a document admitting that the church conducted activities as an organization without registering with the government.

The closing of Shouwang Church comes after authorities made headlines last September for banning Beijing’s largest house church, Zion Church, and confiscating “illegal promotional materials.”

Zion Church had previously rejected requests from government authorities to install closed-circuit cameras. Officials in Beijing argued that the church had held events without registering.

Shouwang Church in the past has been forced to meet in outdoor locations as government pressure made it difficult for the congregation to secure rented or purchased space. As previously reported, the church’s founding pastor was placed under house arrest in 2011 and many church members were arrested after the church began worshiping outdoors after its eviction from a building.

Last July, at least 34 house churches in Beijing signed a joint statement to China’s Communist Party officials decrying what they called an ongoing and worsening crackdown against believers.

“The normal religious lives of believers have been violated and obstructed, causing serious emotional harm and damage to their sense of patriotism, as well as causing social conflict,” the statement read.

Beijing churches are not alone in facing persecution as dozens upon dozens of members of Early Rain Covenant Church in Chengdu have been arrested for worshiping after government officials closed the church last December.

China ranks as the 27th worst nation in the world when it comes to Christian persecution, according to Open Doors USA’s World Watch List. This ranking reflects the increasing implementation of regulations on religion in China that are now “much harsher across the country.”

During his trip to Hong Kong earlier this month, U.S. Ambassador-at-Large for International Religious Freedom, Sam Brownback, said he believes the Chinese government “is at war with faith.”

“It’s a war they will not win,” Brownback declared during a speech at the Foreign Correspondents Club. “The Chinese Communist Party must hear the cry of its people for religious freedom.”

The former Kansas governor and U.S. senator criticized the Chinese government’s treatment of Christians as well as its imprisonment of as many as 1 million Uighur Muslims in internment camps.

ICC Regional Manager Gina Goh stated in a press release that China’s disregard of religious freedom “is deplorable.”

“Christians outside of the state-sanctioned churches can no longer worship without fearing of harassment, detention, or even imprisonment,” Goh stressed. “Even official churches face increasing pressure to exalt the Communist Party over God. The international community should continue to press China over its human rights abuses until it is willing to make positive change.”

China Aid’s Fu had previously warned members of Congress that religious freedom in China has reached the “worst level that has not been seen since the beginning of the Cultural Revolution by Chairman Mao in the 1960s.”

He also warned about a five-year plan to make Christianity more compatible with socialism. That plan, he says, features a “rewrite” of the Bible to “reflect Chinese ethics of Confucianism and socialism.”