It is sunset and the faithful are being called to prayer in one of the largest mosques in the northern Chinese province of Ningxia - except there is no wailing muezzin’s call, just the sound of a tiny congregation shuffling in quietly off the street.

By the time prayers begin, there are only about 40 pairs of shoes in the entrance hall of the Nanguan Mosque that once accommodated hundreds of worshippers from China’s Hui Muslim minority, but this year has seen its congregation shrink sharply.

One reason for the empty prayer mats is a ban by the Chinese government on all Communist Party members from attending daily prayers at mosques.

The call to prayer which once echoed morning and night over the region’s capital, Yinchuan, is banned too. And as a constant reminder of where loyalties must lie, a Chinese flag flutters in the courtyard, an obligatory requirement for all mosques in China since May.

“We are very scared,” one local imam tells the Telegraph, requesting anonymity, as he explains how the Chinese state is now reaching into the lives of Muslims here like never before.

Scared is exactly what China wants. Xi Jinping, the country’s increasingly autocratic president, has vowed to “Sinicise” religion by stamping out what the officially atheist ruling Communist Party considers a worrying trend of Islamisation.