![Undated photo shows Chinese Air Force jet fighters attending the \](http://www.ecns.cn/hd/2018/05/24/45d8b1252fd3492da4bd5b8e4af6dc72.jpg)
Undated photo shows Chinese Air Force jet fighters attending the "Red Arrow -- 2018" drill. The Chinese Air Force began the "Red Arrow -- 2018" combat exercise in the country's northwest desert on May 23, 2018. (Xinhua/Xi Bobo)
![Undated photo shows a Chinese Air Force jet fighter attending the \](http://www.ecns.cn/hd/2018/05/24/9f732e0921fb4b23b93f45fd47fa8e81.jpg)
Undated photo shows a Chinese Air Force jet fighter attending the "Red Arrow -- 2018" drill. The Chinese Air Force began the "Red Arrow -- 2018" combat exercise in the country's northwest desert on May 23, 2018. (Xinhua/Xi Bobo)