Vowing to plant their flag in China and that blood will "flow in rivers," a new video released this week purportedly by the Islamic State group shows ethnic Uighur fighters training in Iraq, underscoring what Beijing sees as a serious threat.
China is worried that Uighurs, a mostly Muslim people from western China's Xinjiang region, have gone to Syria and Iraq to fight for militant groups there, having traveled illegally via Southeast Asia and Turkey.
Islamic State claimed responsibility for the killing of a Chinese hostage in 2015, demonstrating China's concern about Uighurs it says are fighting in the Middle East.