WASHINGTON (Reuters) - The United States is deeply troubled by reports the Chinese government has “harassed, imprisoned, or arbitrarily detained” relatives of Uighur Muslim activists and survivors of internment camps who have made their stories public, U.S. Secretary of State Mike Pompeo said on Tuesday.

Slideshow ( 2 images )

“In some cases, these abuses occurred shortly after meetings with senior State Department officials,” Pompeo said in a statement, reiterating Washington’s call for Beijing to release those detained.

China has been widely condemned for setting up complexes in its remote Xinjiang region that it describes as “vocational training centers” to stamp out extremism and give people new skills. The United Nations says at least 1 million ethnic Uighurs and other Muslims have been detained.

China has denied any mistreatment of Uighurs, and insists Xinjiang is its internal affair.

Any escalation of tensions between Beijing and Washington worries investors, as the world’s two largest economies are also embroiled in a 15-month old trade war. Beijing also views U.S. support for pro-democracy protests in Hong Kong as interfering with its sovereignty.

In his statement, Pompeo referred to several individuals whose families he said were directly impacted by the Chinese government’s treatment of Uighurs, including Zumrat Dawut, who was one of the speakers at an event in New York on the sidelines of the U.N. General Assembly in September.

Dawut had spoken on how she was detained by Chinese authorities this year and was kept in a camp.

“Most recently, Ms Dawut learned her elderly father, who was reportedly detained and interrogated multiple times by Chinese authorities in Xinjiang in recent years, recently passed away under unknown circumstances,” Pompeo said.

The U.S. government last month widened its trade blacklist to include some of China’s top artificial intelligence start-ups and announced visa restrictions on Chinese government and Communist Party officials it believes responsible for the detention or abuse of Muslim minorities.

“We once again call on Beijing to cease all harassment of Uighurs living outside of China ... and to allow families to communicate freely without repercussions,” Pompeo said.

Speaking in Beijing, Chinese foreign ministry spokesman Geng Shuang said the United States had again and again sought to smear the government’s Xinjiang policy, and that there were no “detention camps” in the far western region.

Xinjiang is an internal affair, and the issue there is not a religious or ethnic one, but about preventing terror and separatism, he said.

“China has not relied on starting wars to deal with terrorism, but has used education and training, in accordance with the law, to help people who have been influenced by extremist and terrorist thinking return to society and a normal life,” Geng said.

“We hope that certain U.S. politicians can remove their colored spectacles, cast aside double standards and stop using Xinjiang-related issues to attack and defame China’s words and actions.”