China has been accused by two US-based human rights groups of conducting a "crushing campaign of religious repression" against Muslim Uighurs.
It is being done in the name of anti-separatism and counter-terrorism, says a joint report by Human Rights Watch and Human Rights in China.
It is said to be taking place in the western Xinjiang region, where more than half the population is Uighur.
Detentions and executions:
The report accuses China of "opportunistically using the post-11 September environment to make the outrageous claim that individuals disseminating peaceful religious and cultural messages in Xinjiang are terrorists who have simply changed tactics".
The authors of the report say it is based on previously undisclosed Communist Party and Chinese government documents, local regulations, press reports and local interviews.
The report says the systematic repression of religion in Xinjiang was continuing as "a matter of considered state policy".
Such repression ranges from vetting imams and closing mosques to executions and the detention of thousands of people every year, it claims.
"Religious regulation in Xinjiang is so pervasive that it creates a legal net that can catch just about anyone the authorities want to target," said Sharon Hom, Executive Director of Human Rights in China.
http://news.bbc.co.uk/2/hi/asia-pacific/4435135.stm