LOS ANGELES, CALIFORNIA - DECEMBER 19: Former Vice President Joe Biden speaks during the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Seven candidates out of the crowded field qualified for the 6th and last Democratic presidential primary debate of 2019 hosted by PBS NewsHour and Politico. (Photo by Justin Sullivan/Getty Images)
PHOTO: Justin Sullivan/Getty Images
LOS ANGELES, CALIFORNIA - DECEMBER 19: Former Vice President Joe Biden speaks during the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Seven candidates out of the crowded field qualified for the 6th and last Democratic presidential primary debate of 2019 hosted by PBS NewsHour and Politico. (Photo by Justin Sullivan/Getty Images)
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LOS ANGELES, CALIFORNIA - DECEMBER 19: Sen. Elizabeth Warren (D-MA) speaks as South Bend, Indiana Mayor Pete Buttigieg listens during the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Seven candidates out of the crowded field qualified for the 6th and last Democratic presidential primary debate of 2019 hosted by PBS NewsHour and Politico. (Photo by Justin Sullivan/Getty Images)
PHOTO: Justin Sullivan/Getty Images
LOS ANGELES, CALIFORNIA - DECEMBER 19: Sen. Elizabeth Warren (D-MA) speaks as South Bend, Indiana Mayor Pete Buttigieg listens during the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Seven candidates out of the crowded field qualified for the 6th and last Democratic presidential primary debate of 2019 hosted by PBS NewsHour and Politico. (Photo by Justin Sullivan/Getty Images)
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PHOTO: Maddie McGarvey for CNN
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LOS ANGELES, CALIFORNIA - DECEMBER 19: Democratic presidential candidate former tech executive Andrew Yang  speaks during the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Seven candidates out of the crowded field qualified for the 6th and last Democratic presidential primary debate of 2019 hosted by PBS NewsHour and Politico. (Photo by Justin Sullivan/Getty Images)
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LOS ANGELES, CALIFORNIA - DECEMBER 19: Democratic presidential candidate former tech executive Andrew Yang speaks during the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Seven candidates out of the crowded field qualified for the 6th and last Democratic presidential primary debate of 2019 hosted by PBS NewsHour and Politico. (Photo by Justin Sullivan/Getty Images)
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LOS ANGELES, CALIFORNIA - DECEMBER 19: Former Vice President Joe Biden speaks during the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Seven candidates out of the crowded field qualified for the 6th and last Democratic presidential primary debate of 2019 hosted by PBS NewsHour and Politico. (Photo by Justin Sullivan/Getty Images)
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LOS ANGELES, CALIFORNIA - DECEMBER 19: Sen. Bernie Sanders (I-VT) (R) speaks as former Vice President Joe Biden listens during the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Seven candidates out of the crowded field qualified for the 6th and last Democratic presidential primary debate of 2019 hosted by PBS NewsHour and Politico. (Photo by Justin Sullivan/Getty Images)
PHOTO: Justin Sullivan/Getty Images
LOS ANGELES, CALIFORNIA - DECEMBER 19: Sen. Bernie Sanders (I-VT) (R) speaks as former Vice President Joe Biden listens during the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Seven candidates out of the crowded field qualified for the 6th and last Democratic presidential primary debate of 2019 hosted by PBS NewsHour and Politico. (Photo by Justin Sullivan/Getty Images)
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LOS ANGELES, CALIFORNIA - DECEMBER 19: Democratic presidential candidatte Sen. Amy Klobuchar (D-MN) speaks as Sen. Bernie Sanders (I-VT) listens during the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Seven candidates out of the crowded field qualified for the 6th and last Democratic presidential primary debate of 2019 hosted by PBS NewsHour and Politico. (Photo by Justin Sullivan/Getty Images)
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(CNN) —  

The live feed of the sixth Democratic presidential debate was cut without warning in China Thursday night during a discussion on allegations of human rights abuses in the country’s western region of Xinjiang.

The screen went black just before 9 p.m. ET after PBS moderator Judy Woodruff asked Mayor Pete Buttigieg if the US should boycott the 2022 Beijing Olympics over China’s alleged mass detention of its Uyghur citizens.

The feed from the PBS/Politico debate in Los Angeles remained cut for about nine minutes while candidates were asked about a range of China issues, including the Hong Kong protests and military tensions in the South China Sea.

Censors regularly screen live broadcasts on international media networks in China, ready to cut any segment from the air if it is deemed politically sensitive by the ruling Communist Party.

Viewers know that what they are seeing has been censored because the screen goes black and all sound cuts out.

CNN stories on the Xinjiang detention centers and the protests in Hong Kong are regularly removed from the air by Chinese censors.

The US State Department claims that up to 2 million Muslim-majority Uyghurs may have been detained in mass detention centers in China’s Xinjiang province. Former detainees and activists claim they have been subjected to hash conditions and abuse as they undergo political re-education inside the camps.

Leaked documents from the Chinese government appear to show a program designed to turn members of the Muslim minority into patriotic, Chinese-speaking citizens.

Beijing has strongly denied allegations of human rights abuses at the camps, which it says are “vocational training centers” with a focus on deradicalization and counterterrorism.

Multiple government officials have already claimed that all the “trainees” at the camps have graduated and returned to society, without providing any evidence.