Islamic State militants from China's Uighur ethnic minority have vowed to return home and "shed blood like rivers", according to a jihadist-tracking firm, in what experts said marked the first IS threat against Chinese targets.
The threat came in a half-hour video released Monday by a division of the Islamic State in western Iraq and featuring militants from China's Uighur ethnic group, said the US-based SITE Intelligence Group, which analysed the footage.
China has for years blamed exiled Uighur "separatists" for a series of violent attacks in its western Xinjiang region -- the Uighur homeland -- and warned of the potential for militants to link up with global jihadist groups.
In the video, a Uighur fighter issued the threat against China just before executing an alleged informant.
"Oh, you Chinese who do not understand what people say! We are the soldiers of the Caliphate, and we will come to you to clarify to you with the tongues of our weapons, to shed blood like rivers and avenging the oppressed," according to SITE's translation.
A traditionally Muslim group, many Uighurs complain of cultural and religious repression and discrimination by China.
It appears to be the Islamic State's "first direct threat" against China, Dr. Michael Clarke, an expert on Xinjiang at the National Security College of Australian National University, told AFP.
"It is the first time that Uighur-speaking militants have claimed allegiance to IS," he added.
The video showed China is now "very firmly a target of jihadist rhetoric," Clarke said, marking a shift from years past when it rarely figured in statements by global jihadist groups.
But Clarke said it also could indicate a possible split among Uighur fighters, as it includes a warning to those fighting with the al Qaeda-aligned Turkistan Islamic Party (TIP) in Syria.