Turkey and Britain voiced concern on Monday at China's alleged mistreatment of Uyghurs and other Muslims in its Xinjiang region, with Turkish Foreign Minister Mevlut Cavusoglu calling on Beijing to protect freedom of religion and cultural identity.
The issue came up as UN Human Rights Council opened its main annual session. Diplomats and activists say China has lobbied hard to avoid scrutiny over its policies in Xinjiang and other rights issues at the four-week meeting.
Western countries are looking to Turkey and other members of the Organisation of Islamic Cooperation (OIC) to spotlight what rights groups call internment camps in Xinjiang, a remote western region of China. China says they are re-education and training facilities that have been highly successful in stopping attacks previously blamed on Islamist militants and separatists.
Britain was the only country joining Turkey in raising the issue at Monday's session, where Lord Ahmad, minister of state at the Foreign and Commonwealth Office, said: "We are deeply concerned about the persecution of Uyghur Muslims in Xinjiang".
UN experts and activists say the camps hold a million Uyghurs, who speak a Turkic language, and other Muslims. China has denied accusations of mistreatment and deems criticism within the UN council to be interference in its sovereignty.
Cavuslogu did not specifically mention mass detention camps but he told the Geneva forum that reports of human rights violations against Uyghurs and other Muslims in Xinjiang were serious cause for concern.
A distinction should be made between "terrorists and innocent people", Cavusoglu added.
He then inserted a line into his prepared remarks, adding: "And I have to underline that we support the One China policy".
He was referring to China's stance that the country encompasses Taiwan and autonomous regions including Xinjiang and Tibet.
"We encourage Chinese authorities and expect that universal human rights, including freedom of religion, are respected and full protection of the cultural identities of the Uyghurs and other Muslims is ensured," Cavusoglu said.
China, a member of the 47-member Human Rights Council, did not immediately respond to his remarks, but delegations will be free to reply to allegations later in the session.
China's counter-terrorism and de-radicalisation efforts in Xinjiang should be applauded for creating a new method of tackling the problem, a senior Chinese diplomat told foreign envoys last week.