The US has blacklisted 28 Chinese organisations for their alleged involvement in abuses against ethnic Uighurs in China’s Xinjiang province.
All 28 organisations are now on the so-called Entity List, which bars them from buying products from US companies without approval from Washington.
Those targeted include one of the world’s largest makers of surveillance equipment.
China has not yet commented on the US decision.
A Commerce Department filing said the organisations are “implicated in human rights violations and abuses”.
Rights groups say Beijing is severely persecuting the mostly Muslim Uighurs in detention camps.
China calls these “vocational training centres” to combat extremism.
What has the US done?
These 28 entities are implicated in “China’s campaign of repression, mass arbitrary detention, and high-technology surveillance against Uighurs, Kazakhs, and other members of Muslim minority groups”, the filing reads.
Xinjiang province’s Public Security Bureau is on the list, along with 19 other smaller government agencies.
Hikvision, Dahua Technology and Megvii Technology are among eight commercial groups on the list, all of which specialise in facial-recognition technology. Hikvision is one of the largest surveillance equipment manufacturers in the world.
It is not the first time the US has placed Chinese groups under a trade ban. In May, the Trump administration added telecommunications giant Huawei to the Entity List because of security fears over its products.
Both countries are in the midst of a trade war, and have sent delegations to Washington for a meeting about the tensions later this week.
According to reports in September, the White House is mulling de-listing Chinese companies from US stock exchanges.
What is the situation in Xinjiang?
China says people in Xinjiang are attending “vocational training centres” designed to combat extremism.
But human rights groups and the UN say China is holding up to one million Uighurs and other Muslims in detention camps.
There have been increasingly vocal denunciations from the US and other countries about China’s actions in Xinjiang.
Last week, US Secretary of State Mike Pompeo alleged that China “demands its citizens worship government, not God” in a press conference in the Vatican.
And in July more than 20 countries at the UN Human Rights Council signed a joint letter criticising China’s treatment of the Uighurs and other Muslims.
Who are the Uighurs?
Uighurs are ethnically Turkic Muslims. They make up about 45% of the Xinjiang region’s population; 40% are Han Chinese.
China re-established control in 1949 after crushing short-lived state of East Turkestan.
Since then, there has been large-scale immigration of Han Chinese and Uighurs fear erosion of their culture.
Xinjiang is officially designated an autonomous region within China, like Tibet to its south.