A group of Western ambassadors in Beijing reportedly wrote a letter demanding that China explain its persecution of the Uighur ethnic minority.

China subjects the Uighurs, a majority-Muslim ethnic group, under an unprecedented amount of surveillance, and is accused of imprisoning up to 1 million of them in detention camps and re-education centers.

The Chinese foreign ministry on Friday lashed out at the reported letter, calling the ambassadors "very rude."

China snapped at a report that Western ambassadors in Beijing were planning a rare coordinated meeting to grill officials in Xinjiang, western China, over their persecution of the Uighur ethnic minority.

Reuters reported on Thursday that 15 ambassadors wrote a letter demanding a meeting with Chen Quanguo, the Communist Party secretary on Xinjiang believed to be the architect of the crackdown, so he can explain human rights abuses against the majority-Muslim, Turkic-speaking group.

China has launched an unprecedented crackdown on the Uighurs, subjecting them to thousands of facial-recognition cameras, forcing them to download apps that track their cellphone activity, and allegedly imprisoning up to 1 million of them in detention and re-education camps where many endure psychological and physical abuse.

Beijing justifies its Uighur crackdown as a counterterrorism measure, and has characterized the re-education centers as "free vocational training" camps that make life "colorful."

But despite Beijing insisting its Uighur camps are fun, it has consistently refused to allow UN inspections.

Uighurs make bread under a poster of Chinese leaders, including Mao Zedong and Xi Jinping, in Kashgar, Xinjiang, in 2017. They are subjected to an unprecedented amount of surveillance in their home region. Kevin Frayer/Getty Images

China's foreign ministry on Friday lashed out at the reported letter, calling the ambassadors involved "very rude."

Spokeswoman Hua Chunying told reporters: "I think this is very rude and we cannot accept that."

"We hope that as ambassadors, they can truly fulfill their responsibilities and obligations, play a positive and constructive role in helping their countries to understand China in a true, comprehensive and three-dimensional way, and to promote mutual trust, friendship and cooperation between China and the countries they represent," she added.

Security personnel patrol near a mosque in Kashgar, Xinjiang in November 2017. Associated Press/Ng Han Guan

Hua also accused the signatories of hypocrisy, claiming that all of China's ethnic groups — including the Uighurs and Hans, which are dominant in China — live in harmony and that the Uighur camps were a means of assimilating Uighurs.

Hua said: "I think you may wish to interview these ambassadors to China and ask them whether they have done their homework seriously before writing this letter. Do they not know that in China, apart from the Han and Uighurs, there are 54 other ethnic minorities?"

"You can also ask them whether in their own countries, such as the US and Canada, ethnic minorities have to learn English as well? If ethnic minorities learn English, would this be considered the eradication and forced assimilation?"

Chen Quanguo, the intended recipient of the 15 diplomats' letter and the man believed to be behind the Uighur crackdown. Here he is in Beijing in 2017. Reuters/Tyrone Siu

The US was not part of the letter to Chen, which carried the names of ambassadors from Britain, Canada, France, Switzerland, the EU, Germany, the Netherlands, Australia, Ireland, Sweden, Belgium, Norway, Estonia, Finland and Denmark, Reuters reported.

Canada reportedly spearheaded the writing of the letter.

Earlier this week Beijing told Congress to back off in response to a bipartisan bill designed to punish China over its persecution of its Muslim ethnic minority, known as the Uighurs.

Read more: China tells Congress to back off after planned legislation looks to sanction Beijing over imprisoning Muslims

