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 also met privately with Turkish President Recep Tayyip Erdogan during a visit coinciding with a spike in new virus infections that follows an easing of restrictions at the start of the month.
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 and Turkish Foreign Minister Mevlut Cavusoglu tweeted that he had "conveyed our sensitivity and thoughts on Uyghur Turks" to Wang.
Turkey and China "will enhance our cooperation on (the) fight against (the) pandemic", as well as on vaccines, Cavusoglu's tweet added.
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!"
Turkish police forced a smaller group of protesters to move away from China's embassy in Ankara.
Rights groups believe at least one million Uyghurs and other mostly Muslim minorities have been incarcerated in camps spread out across the vast northwestern Chinese region of Xinjiang.
Beijing strongly denies the allegations and says it is organising training programmes and work schemes to help stamp out extremism in the region.
- 'Frustrated' -
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?" protester Abdullatif Ragip told AFP.
"They do a lot of harm in East Turkestan," the 62-year-old said.
Cavusoglu has argued that Ankara's ratification of the extradition agreement would not mean it "will release Uyghurs 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.
Cavusoglu's tweet said he and Wang "discussed (the) potential of economic cooperation" on the 50th anniversary of Ankara and Beijing establishing diplomatic ties.
"We are scared about the future," said protesters Rahile Seker.
"What will happen to our children? Turkey should open its eyes and stand by innocent Uyghurs."
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.