UPDATE 1-U.S. sanctions four Chinese officials over abuses in Xinjiang

(Adds details, background, White House comment, updates headline)

WASHINGTON, July 9 (Reuters) - The United States on Thursday imposed sanctions on Chinese officials, including a member of the country's powerful Politburo, accusing them of serious human rights abuses against the Uighur Muslim minority, a move likely to further ratchet up tensions between Washington and Beijing.

The sanctions that include the Xinjiang region's Communist Party Secretary Chen Quanguo and the Xinjiang Public Security Bureau were announced amid already-high tensions between Washington and Beijing over China's handling of the coronavirus pandemic and its tightened grip on Hong Kong.

"The United States calls upon the world to stand against the CCP's acts against its own minority communities in Xinjiang, including mass arbitrary detention, forced labor, religious persecution, and forced birth control and sterilization," a White House official said.

The Chinese embassy in Washington did not immediately respond to a request for comment.

However, China denies mistreatment of the minority group and says the camps provide vocational training and are needed to fight extremism.

The sanctions are imposed under the Global Magnitsky Act, a federal law that allows the U.S. government to target human rights violators around the world with freezes on any U.S. assets, U.S. travel bans and prohibitions on Americans doing business with them.

The sanctions were imposed on Chen, a member of China's powerful politburo; Zhu Hailun, a former deputy party secretary of the region; Wang Mingshan, the director and Communist Party secretary of the Xinjiang Public Security Bureau; and former party secretary of the bureau Huo Liujun.

U.S. Secretary of State Mike Pompeo in a statement said he was also imposing further visa restrictions on Chen, Zhu, and Wang, barring them and their immediate family from the United States.

The U.S. Treasury Department said that Chen, the highest-ranking Chinese official to be hit with sanctions, implemented "a comprehensive surveillance, detention, and indoctrination program in Xinjiang, targeting Uighurs and other ethnic minorities" through the Xinjiang Public Security Bureau.

The United Nations estimates that more than a million Muslims have been detained in camps in the Xinjiang region.

China threatened retaliation after U.S. President Donald Trump signed legislation in June with little fanfare, calling for sanctions over the repression of China's Uighurs. (Reporting by Daphne Psaledakis, Alexandra Alper, Matt Spetalnick and Tim Ahmann Editing by Chizu Nomiyama and Marguerita Choy)