BEIJING — A group of U.S. lawmakers has urged President Donald Trump’s administration to impose sanctions including asset freezes and visa bans on Chinese officials and companies allegedly tied to a stifling security crackdown and the mass internment of ethnic minority Muslims in camps in a far western region.

The lawmakers sent a letter to Secretary of State Mike Pompeo and Treasury Secretary Steve Mnuchin urging the government to apply sanctions to address the “ongoing human rights crisis” in the region of Xinjiang, in the latest sign that the detentions are raising concerns among Western leaders and governments.

Muslim ethnic minorities in Xinjiang are being detained and tortured and face “egregious restrictions on religious practice and culture” and other abuses, said the letter, which was signed by Florida Sen. Marco Rubio and New Jersey Rep. Chris Smith and 15 others. It was provided to the media on Wednesday.

The letter singles out Xinjiang’s top official, Chen Quanguo, accused by many of turning the region into a police surveillance state and implementing a system of internment camps, also known as “re-education centers,” where members of the Uighur (‘WEE-gur) and other Muslim minorities are locked up for months without trial.

“The detention of as many as a million or more Uighurs and other predominantly Muslim ethnic minorities in ‘political reeducation’ center or camps requires a tough, targeted, and global response,” the letter said.

Former detainees who spoke to The Associated Press described the internment camps as facilities policed by armed guards where Muslims were forced to disavow their religious beliefs, criticize themselves and their loved ones and give thanks to the ruling Communist Party. Beatings and deaths have been reported despite authorities’ tight control on information from the region.