The United States Commerce Department on Monday added 11 Chinese companies implicated in what it called human rights violations in connection with China's treatment of its Uighurs in Xinjiang in western China to the US economic blacklist.

The department said the companies were involved in using forced labour by Uighurs and other Muslim minority groups. They include numerous textile companies and two firms the government said were conducting genetic analyses used to further the repression of Uighurs and other Muslim minorities.

Blacklisted firms cannot buy components from US companies without US government approval.

It was the third group of companies and others in China added to the US entity list, after two rounds in which the Trump administration cited 37 companies and others that it said were involved in China's repression in Xinjiang.

"Beijing actively promotes the reprehensible practice of forced labor and abusive DNA collection and analysis schemes to repress its citizens," Commerce Secretary Wilbur Ross said in a statement.

The Chinese Embassy in Washington did not immediately comment.

The companies added to the blacklist include KTK Group Co, which produces more than 2,000 products used to build high-speed trains, from electronics to seats; and Tanyuan Technology Co, which assembles high thermal conductive graphite reinforced aluminium composites, including some for consumer electronic products.

Also on the blacklist is Hetian Haolin Hair Accessories Co. On May 1, US Customs and Border Protection (CBP) said it was halting imports of the company's hair products, citing evidence of forced labour.

On July 1, CBP seized in Newark a shipment of almost 13 tons of hair products worth more than $800,000 with human hair that originated in Xinjiang.

Commerce previously added 20 Chinese public security bureaus and companies including video surveillance firm Hikvision, as well as leaders in facial recognition technology SenseTime Group Ltd and Megvii Technology in connection with China's treatment of Muslim minorities.