Protesters, who are members of the Muslim Solidarity Movement, hold placards during a protest against violence and the treatment of Uighur Muslims by the Chinese government, in Bandung, West Java, Indonesia, December 21, 2018 in this photo taken by Antara Foto. Antara Foto/Novrian Arbi/ via REUTERS

JAKARTA (Reuters) - Hundreds of Muslims held a rally outside the Chinese embassy in the Indonesian capital, Jakarta, on Friday to protest against the treatment of members of the mostly Muslim ethnic Uighur minority in China’s far western Xinjiang region.

A United Nations panel of human rights experts said in August it had received many credible reports that 1 million ethnic Uighurs in China were being held in what resembled a “massive internment camp that is shrouded in secrecy”.

The United Nations called for the immediate release of those detained on the “pretext of countering terrorism”.

Opposition groups in Indonesia, has the world’s largest Muslim population, have criticized President Joko Widodo for not providing enough support for China’s Uighur community.

“The United Nations must speak out, the OIC (Organisation of Islamic Cooperation) must speak out, Muslims must take a stand against the Chinese government,” said protester Ridwan Abdul Ridho said on Friday.

China says Xinjiang faces a threat from Islamist militants and separatists. It rejects all accusations of mistreatment and denies mass internment, although Chinese officials have said some citizens guilty of minor offences were being sent to vocational centers to work.

China worries that Uighurs, who speak a Turkic language, have gone to places like Afghanistan, Pakistan, Syria and Iraq to fight for militants.

The Indonesian foreign ministry said it had summoned the Chinese envoy in Jakarta to “convey concern from various parties in Indonesia on the condition of people of Uighur in China” and called on China to respect freedom of religion.