A former Muslim leader at China's largest mosque in the country's far-western Xinjiang region was incarcerated by Chinese authorities in 2017 as he was accused of having spread extremism, sources close to the matter said Sunday.

In addition to the person who led prayers in the mosque, other religious leaders have been also detained, the sources said, amid accusations that the Communist-led government has infringed on the human rights of the Muslim Uyghur minority in the region.

Photo taken May 11, 2021 shows the inside of the Id Kah mosque. (Kyodo)

The former imam at the Id Kah mosque was sentenced to 15 years in prison, the sources said. China's move may come under fire from the United States and other democratic nations that have lambasted the alleged repression of the Uyghurs as amounting to a "genocide."

The current imam at the mosque, however, has denied religious oppression by the ruling Communist Party.

China has been criticized for mass detention of the Muslim Uyghur minority who oppose growing state surveillance under the re-education campaign in Xinjiang.

President Xi Jinping's leadership has consistently said its internment camps are vocational training centers established to combat terrorism and religious extremism preemptively, urging the United States not to interfere in its "internal affairs."

In March, meanwhile, the United States condemned the "genocide" that has occurred against the Muslim Uyghur minority in China in an annual human rights report issued for the first time under the administration of President Joe Biden, who took office in January.

The abusive treatment of ethnic and religious minority groups in the Xinjiang region includes the arbitrary imprisonment or other severe deprivation of physical liberties of more than 1 million civilians, forced sterilization, coerced abortion, rape and forced labor, the 2020 report said.

China has been facing boycotts of the 2022 Winter Beijing Olympic by democratic countries denouncing its alleged human rights violations against the nation's Muslim Uyghur minority in Xinjiang.

A Chinese flag is seen hoisted at the Id Kah mosque in the country's far-western Xinjiang autonomous region on May 2, 2021. (Kyodo) ==Kyodo