WASHINGTON, (Reuters) – The U.S. Commerce Department placed restrictions on exports to several Chinese companies Thursday due to national security concerns. Washington claims that the Uyghurs were involved in oppression and Beijing is helping them with their military operations.

Senior administration officials said that the Commerce Department would announce on Thursday a number of actions targeting Chinese businesses who Washington claims use biotechnology or surveillance to violate human rights.

The official cited their involvement in China’s oppression of the ethnic Uyghurs. He said that the Commerce Department would add the Academy of Military Medical Sciences of China and 11 of its research institutes onto its list of institutions and companies, restricting exports.

This U.S. action came after a ban placed by the U.S. on Chinese facial recognition firm SenseTime. It could further aggravate already strained relations between Beijing, Washington.

The senior official spoke out to reporters about the People’s Republic of China, saying that these actions are part of the larger context of government efforts to combat the misuse of technology for surveillance and, in some cases, large-scale repressive social control.

U.N. officials and rights groups have estimated that over a million Uyghurs as well as members of other Muslim minority minorities were held in detention in China’s remote-west region, Xinjiang, in the recent years.

China has denied any abuses of Xinjiang.