Last week's terrorist attack in the Xin-jiang Uygur autonomous region is ready proof that the "three evil forces" of terrorism, separatism and extremism have once again raised their ugly heads in the region.

Terrorism is not a homegrown problem in Xinjiang, and there has been concern about foreign infiltration for years. Media reports offer clues that there was foreign involvement in the latest attack, so wider and more intensified international cooperation is undoubtedly needed to root out the three evils.

A member of the "East Turkistan" movement allegedly participated in last week's attack after returning from fighting in Syria. In recent years, Chinese national security authorities have repeatedly warned that the flow of "East Turkistan" members from outside the country to Xinjiang posed a threat to local stability.