Thousands of Uighurs were sent to work in factories across China -- “under conditions that strongly suggest forced labour.”

There were no immediate reports of injuries or damage.

U.S. Secretary of State Mike Pompeo said the documents underscored "an overwhelming and growing body of evidence'' that China's leaders are responsible for gross human rights violations in the Xinjiang region.

A spokesman for Global Affairs Canada said Monday the government is deeply concerned by Huseyin Celil's detention, as well as the human-rights situation for Muslim Uighurs and other minorities in China.

United Nations experts and rights groups estimate more than a million Uighurs and members of other ethic groups have been detained in camps in a far-reaching campaign that has triggered an international backlash.

The State Department announcement did not name the officials subject to the visa restrictions.

The blacklist effectively bars U.S. firms from selling technology to the Chinese companies without government approval.

The United Nations says at least 1 million ethnic Uighurs and other Muslims have been detained in what China describes as "vocational training centers" to stamp out extremism and give people new skills.

China has agreed to let 2,000-plus ethnic Kazakhs leave, but they did not say who could leave or why.

The report was a rare move by the ruling Communist Party to publicly outline what it is trying to achieve with what former detainees have characterized as political indoctrination camps where they are forced to denounce Islam and profess loyalty to the party.