Nearly 1,000 Uyghurs rallied in Istanbul on Thursday as Chinese Foreign Minister Wang Yi met his Turkish counterpart for talks expected to focus on coronavirus vaccines and the countries' extradition treaty.
Wang was also due to meet Turkish President Recep Tayyip Erdogan in Ankara during a visit that coincides with a sharp spike in new virus infections that follows an easing of some restrictions.
Turkey is using the Chinese firm Sinovac's CoronaVac jab in its inoculation effort and is currently negotiating new deliveries.
But the country's 50,000-strong Uyghur community fears that China is making new shipments dependent on Turkey's ratification of an extradition treaty that the parliament in Beijing approved late last year.
Both countries officially deny any such link.
The protesters waved sky blue flags of Uyghur separatists' self-proclaimed state of East Turkestan as they gathered in Istanbul's historic old town chanting "China, stop the genocide!"
Rights groups believe at least one million Uyghurs and other mostly Muslim minorities have been incarcerated in camps spread out across the vast northwestern region of Xinjiang.
Beijing strongly denied the allegations and says it is organising training programmes and work schemes to help stamp out extremism in the region.
Uyghurs speak a Turkic language and have cultural ties with the mostly Muslim but officially secular country that make it a favoured destination for avoiding persecution back home.
"I am frustrated. Why is Turkey receiving the Chinese foreign minister?" one of the protesters Abdullatif Ragip, 62, told AFP.
"They do a lot of harm in East Turkestan."
Turkish Foreign Minister Mevlut Cavusoglu has argued that Ankara's ratification of the extradition agreement would not mean that Ankara "will release Uighurs to China".
But Uyghurs in Turkey are pressing Erdogan's government to join a new wave of Western sanctions against Chinese officials over their actions in Xinjiang.
"We are scared about the future. What will happen to our children? Turkey should open its eyes and stand by innocent Uyghurs," said Rahile Seker, a female protester in Istanbul.
Another demonstrator, Feyzullah Kaymak, said Turkey must ask the Chinese foreign minister what happens in camps.
"We want Turkey to ask the Chinese foreign minister what happens over there... We want Turkey to raise its voice."
The Turkish government released images of Cavusoglu and Wang sitting down for talks in Ankara but the two ministers have scheduled no press events.