China's foreign ministry said Wednesday it wants to work with the international community to fight terrorists, following the purported release by Islamic State (IS) of a video showing Chinese Uyghur fighters in training.

A half-hour video was released on Monday by a division of the IS in western Iraq, featuring militants from China's Uyghur ethnic group, according to US-based SITE Intelligence Group which monitors militant groups online.

"We oppose any form of terrorism and proactively participate in international cooperation to crack down on terrorism," Geng Shuang, a spokesperson for China's foreign ministry, told a daily news briefing on Wednesday, noting however that he was not aware of the video.

The IS video showed fighters, including heavily armed children, giving speeches, praying, and killing other "informants." Global Times was not able to independently verify the authenticity of the video.

Separatists want to establish an independent state called East Turkestan, and they have stirred up tensions in Northwest China's Xinjiang Uyghur Autonomous Region by killing hundreds of innocent people in the past few years.

"East Turkestan forces are a serious threat to China's security and we are willing to work with the international community to jointly crack down on East Turkestan separatist and terrorist forces," Geng said.

The IS had claimed responsibility for the killing of ­Chinese hostage Fan Jinghui in 2015.

Some Chinese Uyghur terrorists have gone to Syria and Iraq to fight for militant groups there, having traveled illegally via Southeast Asian countries and ­Turkey.

Wang Hongwei, a professor at the School of Public Administration and Policy at the Renmin University of China, told the Global Times that international cooperation against terrorism is not easy as some countries are using counterterrorism as an instrument of political plot.

"The video means there is a concrete threat from the terrorists and we need to strengthen our security forces in ­Xinjiang," said Wang, ­denouncing the double standard of Western­ media on the security in Xinjiang.­

"It may be a normal act of the terrorists, but it does not mean we should not take it seriously."

The release of the video came the same day when a joint counterterrorism drill was held in Xinjiang.

The local government of Hotan prefecture in Xinjiang is offering a reward of up to 5 million yuan ($726,744) to people who provide information on terror activities.

Li Wei, chief of the Counter-terrorism Research Center at the China Institute of Contemporary International Relations, said it is also possible that the Eastern Turkestan terrorists are just showing off.

"[The threatening video] has no big difference from those that had been released by the IS to other countries," Li said. "It may also be that the Eastern Turkestan terrorists are hoping to make international headlines with the help of the more high-profile IS," Li added.