Chinese police have detained 36 people Wednesday after a raid on a bible school run by an underground Protestant church. The raid comes amid tough persecution on Christians in China who continue to worship outside the official Communist Party-controlled church.

China Aid Association said in a letter to Associated Press that students, teachers and leader of the underground church were rounded up and taken away in vans after around 50 officers surrounded the school in the eastern province of Anhui.

According to the US-based group, the owner of the school, Chu Huaiting and the vice president of the Chinese House Church Alliance, was later arrested at his home.

Thousands of copies of religious literature were confiscated from the school by the authorities, reports China Aid Association, while blankets made by the students in the school to support themselves with were also confiscated.

AP reported that a female officer, who refused to give her name, answered the police department phone in the town of Huaibei, where the school was situated, but said she did not know of the reported raid.

Religious freedom advocates are concerned that the recent adoption of new rules on religious organisations in China has led to increased persecution by local authorities.

According to China Aid Association, there are around 300,000 worshippers in unofficial congregations of religious literature.

In China, Christians may only practise their faith under the auspices of the official Three Self Patriotic Movement which was established after the1949 communist revolution saw the expulsion of foreign missionaries and church leaders.

The finances, leadership and doctrinal issues, and religious education, particularly among young people, are tightly controlled by the ruling party.