Firefighters work to extinguish the blaze at a forest in the Greater Hinggan Mountains, north China's Inner Mongolia Autonomous Region, June 2, 2018. No casualties or damage of major facilities have been reported so far. Nearly 2,000 forest police and fire fighters have been mobilized to battle forest fires. (Xinhua/Wu Shikang)

Firefighters work to extinguish the blaze at a forest in the Greater Hinggan Mountains, north China's Inner Mongolia Autonomous Region, June 2, 2018. No casualties or damage of major facilities have been reported so far. Nearly 2,000 forest police and fire fighters have been mobilized to battle forest fires. (Xinhua/Wu Shikang)

Firefighters work to extinguish the blaze at a forest in the Greater Hinggan Mountains, north China's Inner Mongolia Autonomous Region, June 2, 2018. No casualties or damage of major facilities have been reported so far. Nearly 2,000 forest police and fire fighters have been mobilized to battle forest fires. (Xinhua/Wu Shikang)