Arsenal’s Mesut Ozil, a German footballer of Turkish origin, on Friday expressed support for Uighurs in Xinjiang and criticised Muslim countries for their failure to speak up for them.

“Korans are being burnt... Mosques are being shut down ... Muslim schools are being banned ... Religious scholars are being killed one by one ... Brothers are forcefully being sent to camps,” Ozil wrote in Turkish on his Twitter account.

“The Muslims are silent. Their voice is not heard,” he wrote on a background of a blue field with a white crescent moon, the flag of what Uighur separatists call East Turkestan.

China has faced growing international condemnation for setting up a vast network of camps in Xinjiang aimed at homogenising the Uighur population to reflect China’s majority Han culture. Rights groups and experts say more than one million Uighurs and people of other mostly Muslim ethnic minorities have been rounded up in the camps in the tightly-controlled region.

After initially denying the camps existed, China describes them as vocational schools aimed at dampening the allure of Islamist extremism and violence.

Turkey, which takes its name from Turkic people who migrated from central Asia, is home to an Uighur community and has regularly raised concerns about the situation in Xinjiang.

In his tweet, Ozil said Western states and media had kept the Uighur issue on their agenda and added: “what will be remembered years later would not be the torture by the tyrants but the silence of their Muslim brothers.”

Arsenal moved to distance themselves from Ozil’s comments in a bid to limit fallout in China, where the club has numerous commercial interests.

“The content published is Ozil’s personal opinion,” the club said in a Chinese language post Saturday on its official account on the Twitter-like Weibo platform. “As a football club, Arsenal has always adhered to the principle of not involving itself in politics.”

But a few angry fans called for a ban on airing Arsenal games featuring Ozil.

“I hope they ban Ozil’s matches and business activities (in China),” wrote one Weibo user.

Another Chinese fan said she “cried last night” after reading the post, which the star had also uploaded to Instagram.

“For over a decade, I’ve worn an Arsenal jersey with Ozil’s number. It will never be worn again,” she wrote on Weibo.

The 31-year-old footballer sparked controversy last year when he was photographed with Turkish President Recep Tayyip Erdogan, raising questions about his loyalty to Germany on the eve of their 2018 World Cup campaign.

Ozil later quit the national squad, accusing German football officials of racism. Erdogan was Ozil’s best man when the footballer was married in Istanbul this year.