Saudi Arabia, Russia and 35 other states have written to the United Nations supporting China's policies in its western region of Xinjiang, in contrast to strong Western criticism.

Key points: China is accused of detaining more than a million Muslims in mass internment camps

China is accused of detaining more than a million Muslims in mass internment camps 22 countries this week publicly called for an end to arbitrary detention in Xinjiang

22 countries this week publicly called for an end to arbitrary detention in Xinjiang Saudi Arabia, like other Muslim-majority countries, has failed to criticise China's treatment of Muslims

China has been accused of detaining a million Muslims and persecuting ethnic Uyghurs in Xinjiang, and 22 ambassadors signed a letter to the UN Human Rights Council this week criticising its policies.

Countries including Australia, Britain, Germany and Japan called upon China to "refrain from the arbitrary detention and restrictions on freedom of movement of Uyghurs, and other Muslim and minority communities in Xinjiang".

But in a show of China's growing diplomatic clout, an opposing letter accused the West of "politicising human rights" and commended what it called China's "remarkable achievements" in human rights.

China says Uyghrs are undergoing "re-education" and vocational training. ( Reuters: Thomas Peter )

In addition to Saudi Arabia and Russia, the pro-China letter was signed by ambassadors from many African countries, North Korea, Venezuela, Cuba, Belarus, Myanmar, the Philippines, Syria, Pakistan, Oman, Kuwait, Qatar, the United Arab Emirates and Bahrain.

"Faced with the grave challenge of terrorism and extremism, China has undertaken a series of counter-terrorism and de-radicalisation measures in Xinjiang, including setting up vocational education and training centres," it said.

The letter said security had returned to Xinjiang and the fundamental human rights of people of all ethnic groups there had been safeguarded.

There had been no terrorist attack there for three years and people enjoyed a stronger sense of happiness, fulfillment and security, the letter added.

The ruling Chinese Communist Party maintains that its repressive measures in Xinjiang are "counter-terrorism" tactics against ethnic Uyghur separatists and Islamic extremists.

While only several thousand Uyghur Muslims are estimated to have travelled to Syria and Iraq to fight for Islamic State, some 10 per cent of the entire Uyghur population is estimated to have been detained.

Beijing has established a wide-reaching surveillance state in Xinjiang and has said it wants to "Sinicise Islam" — a hardline policy increasingly referred to by observers as "cultural genocide" against the Turkic minority group.

Satellite images have documented the growth of Xinjiang's disputed vocational centres. ( ABC News/Google Earth/Digital Globe )

A report from Amnesty International in 2018 claimed that public expressions of faith were now deemed "extremist" by authorities, including growing a beard, praying or fasting during the Islamic holy month of Ramadan.

Those in detention camps are reportedly forced to chant slogans, watch propaganda videos, denounce their religion and pledge loyalty to the communist party in overcrowded cells.

Beijing has denied any human rights violations in the region and Chinese Ambassador Xu Chen, speaking at the close of the Council's three-week session on Friday, said China highly appreciated the support it had received from the signatories.

"What happened around the world, particularly in developing countries like China and African countries, speaks the truth that without development, there are no human rights to talk about," he said earlier in the week at the Council, as quoted by Chinese state news agency Xinhua.

No leader of a major Muslim-majority country has publicly condemned the treatment of Muslims in Xinjiang, with many observers noting significant foreign investment from Beijing across the Muslim world, including via the Belt and Road initiative.

"It is a fact that the peoples of China's Xinjiang region live happily in China's development and prosperity," Turkish President Tayyip Erdogan, who is a staunch supporter of other Muslim minority groups including the Rohingya and Palestinians, was recently quoted by Chinese state media as saying.

"Turkey does not permit any person to incite disharmony in the Turkey-China relationship," Mr Erdogan added.

"Turkey firmly opposes extremism and is willing to increase mutual political trust with China and strengthen security cooperation."

Reuters/ABC