Students must also not read scriptures in classes or in religious buildings, the bureau said, adding that all students and teachers should heed the notice and work to strengthen political ideology and propaganda, reported Reuters though the news agency said it was not able to independently verify it.
The crackdown follows worries over growing Muslim influence in China in recent years, sparked in part by violence in Xinjiang. The Chinese-speaking Hui, who are culturally more similar to the Han Chinese majority than to Uighurs, have also come under scrutiny from some intellectuals, who fear creeping Islamic influence on society.
China is an atheist, communist state but law formally grants religious freedom for all, but regulations on education and protection of minors also say religion cannot be used to hinder state education, or children taught to believe in a religion, rather than communism.
A picture of the notice was shared online by Xi Wuyi, a Marxist scholar at the state-backed Chinese Academy of Social Sciences and an outspoken critic of rising Islamic influence in China, reported news agency ANI.
The Gansu Government banned religion in nurseries after a video of a young girl reciting the Quran was posted online, two years ago.
China announced new regulations on religious affairs in October last year. They are due to take effect in February and endeavour to enhance oversight of religious education and provide for greater regulation of religious activities.
Last summer, a Sunday School ban was introduced in the southeastern city of Wenzhou, sometimes known as "China's Jerusalem" due to its large Christian population, but Christian parents found ways to teach their children about their religion, regardless.
(With inputs from Reuters and ANI)