 Although there are no definitive figures on the number of underground Christians in China , some estimates have put their total number in excess of 70 million . At least 40 Catholic bishops operate independent of official sanction , and some are under surveillance , house arrest , detention , or have disappeared . Several leaders and members of underground Protestant churches have also been detained and sentenced to reeducation through labor or prison terms . Violent raids and demolitions have been carried out on underground churches , sometimes resulting in injury to congregants inside . Chinese officials have labelled several underground Protestant churches as a xie jiao ( translated literally as " evil religion " ) , or cult , thus providing a pretext for harsher punishment of members . 
