Across much of China, the authorities are encouraging women to have more children, but in the Xinjiang region, China is forcing them to have fewer, tightening its grip on Muslim ethnic minorities and trying to orchestrate a demographic shift that will diminish their population growth.

Birthrates in the region have already plunged in recent years as the use of invasive birth control procedures has risen, according to reports by a noted researcher, Adrian Zenz, along with The Associated Press.

While the authorities have said the birth control procedures are voluntary, interviews with more than a dozen Uyghurs, Kazakhs and other Muslim women and men from Xinjiang, as well as a review of official statistics, government notices and reports in the state-run media, depict a coercive effort by the Chinese Communist Party to control the community’s reproductive faculties. The authorities pressured women to use IUDs or get sterilized. As they recuperated at home, government officials were sent to live with them to watch for signs of discontent; one woman described having to endure her minder’s groping.

If they had too many children or refused contraceptive procedures, they faced steep fines or, worse, detention in an internment camp. In the camps, the women were at risk of even more abuse. Some former detainees say they were made to take drugs that stopped their menstrual cycles. One woman said she had been raped in a camp.