The United States is adding eight Chinese technology companies to its trading blacklist, barring some major producers of surveillance equipment from working with American companies.

The Commerce Department on Monday said it was adding 28 entities to the list that have been implicated in human rights violations and abuses in the implementation of China’s campaign of repression, mass arbitrary detention, and high-technology surveillance against Uighurs, Kazakhs, and other members of Muslim minority groups” in the country’s Xinjian region.

The listed entities include Chinese state security bureaus, as well as the eight companies.

The list includes municipal and county public security bureaus and the Xinjiang Police College.

US officials said the announcement was not tied to this week’s resumption of trade talks with China.

Being added to the “Entity List” bars companies or other entities from buying parts and components from US companies without US government approval.

The Commerce Department previously added Huawei Technologies Co and more than 100 affiliates to the Entity List.

In April, a bipartisan group of US lawmakers urged the move against Chinese companies it called “complicit in human rights abuses” and specifically cited Hikvision and Dahua.

China faces growing condemnation from Western capitals and rights groups for setting up facilities that UN experts describe as mass detention centers holding more than one million ethnic Uighurs and other Muslims.