The United States Thursday placed several Chinese biotechnology companies accused of advancing high-tech surveillance on the Uyghur minority on a trade blacklist.

The Commerce Department restricted sensitive exports to the Academy of Military Medical Sciences and 11 of its research institutes over its biotechnology work including "purported brain-control weaponry," a notice said.

Human rights groups have recounted unprecedented surveillance of the mostly Muslim Uyghur people in the northwestern region of Xinjiang including tracing with DNA and artificial intelligence operations to recognize and monitor faces.

The research institutes targeted by the latest U.S. actions include centers focused on blood transfusions, bioengineering and toxicology.

"The scientific pursuit of biotechnology and medical innovation can save lives. Unfortunately, the PRC is choosing to use these technologies to pursue control over its people and its repression of members of ethnic and religious minority groups," Commerce Secretary Gina Raimondo said in a statement.

"We cannot allow U.S. commodities, technologies and software that support medical science and biotechnical innovation to be diverted toward uses contrary to U.S. national security," she said.

Rights experts, witnesses and the U.S. government say that more than a million Uyghurs and other Turkic-speaking Muslims are incarcerated in camps in an effort to root out their Islamic cultural traditions and forcibly homogenize them into China's Han majority.

The United States has described the campaign as genocide and, citing the rights concerns, plans a boycott of official representation at the Beijing Winter Games next year.

Beijing describes the sites as vocational training centers.