The Islamic State is now setting its sights on China, on Monday releasing a half-hour video in which the terrorist group pledged to "shed blood like rivers" in attacks against Chinese targets. Experts say it's the first threat the terrorist organization has leveled against China.

"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," an Islamic State fighter said in the video, which was analyzed and translated by the US-based SITE Intelligence Group. The video showed fighters including heavily armed children praying, giving speeches, and executing suspected informants.

The video appeared to be the group's "first direct threat" against China, Michael Clarke of the Australian National University told AFP.

At first glance, China may seem like a strange target for the group, also known as ISIS, ISIL, or Daesh. It has no real military footprint in the Middle East, and while Beijing is getting more involved in the region's energy business, it's not involved in the US-led anti-ISIS coalition in Iraq and Syria. But experts say China entered the terrorist group's crosshairs over its treatment of ethnic-minority Muslims, the Uighurs, who are concentrated in the western Chinese province of Xinjiang.

Beijing is taking an increasingly hard line against unrest there. On Monday, thousands of police officers — backed by helicopters and armored vehicles — staged a mass rally, the fourth this year, as a show of force, Reuters reported. A Xinjiang Communist Party official pulled no punches as 1,500 cops were dispatched to problematic cities.

"Bury the corpses of terrorists and terror gangs in the vast sea of the people's war," Reuters reported the official saying.

Iraqi security forces with a seized ISIS flag after driving ISIS militants out of an airport in southwest Mosul, Iraq, on February 23. REUTERS/Zohra Bensemra

Amnesty International slammed the Chinese government for its past crackdowns on the group, including repressing religious ceremonies and jailing Uighurs. China's "anti-Islamic policies have pushed some even moderate Muslims to radical outlets," said Dru Gladney, an expert on Western China at Pomona College.

A 2016 study from New America, a Washington-based think tank, found 114 Uighurs from Xinjiang joined ISIS. Xinjiang furnished the highest number of foreign ISIS fighters from any one province of the world outside Saudi Arabia and Tunisia, the study found.

The video could garner ISIS more publicity in Western China and spark inspiration for new attacks, Gladney told Foreign Policy. But he cautioned it didn’t necessarily mean ISIS would begin directly coordinating terrorist assaults in China.

Ethnic Uighurs have carried out terrorist attacks already, including a May 2014 attack in the Xin­jiang region's capital of Urumqi that killed 43 and wounded 90. But for the most part, Uighur extremists carry out attacks on a much smaller and less coordinated scale. That most likely won't change, despite newfound ISIS-backing, Gladney said.

But the Chinese government's heavy-handed tactics to root out extremism, including military mobilizations and violent repression, could backfire and fuel the rise of more extremism, he added. "They have been trying to swat flies with baseball bats," he said.