The Islamic State terror group released a half-hour video on Monday in which it pledged to plant its flag in China, setting sight on the most populous country in the world, saying that blood will ''flow in rivers''.
The new video, purportedly released by ISIS militants from China's Uighur ethnic minority, shows them undergoing training in Iraq, Reuters reported on Thursday.
The video, which marks the first IS threat to China, was analysed by the US-based SITE Intelligence Group. It showed fighters, including heavily-armed children, praying, giving speeches, and executing suspected informants.
China, according to the Reuters report, is worried that Uighurs have gone to Syria and have joined Islamic State, having travelled illegally via Southeast Asia and Turkey.
For years, China has blamed exiled Uighur ''separatists'' for a series of violent attacks in its western Xinjiang region, 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,'' SITE's translation of a video shot was quoted by AFP as saying.
One shot shows Chinese President Xi Jinping giving way to flames in front of a Chinese flag.
''Hey, brothers! Today, we are fighting with infidels across the world! I'm telling you this, 'Come and live here! Stay strong!','' one of the fighters in the video was quoted by Reuters as saying.
''We will certainly plant our flag over America, China, Russia, and all the infidels of the world,'' he said.
Chinese foreign ministry spokesman Geng Shuang said on Wednesday he was not aware of the video and had not seen it.
''But one point is very clear. We oppose any form of terrorism and proactively participate in international cooperation to crack down on terrorism,'' said Geng.