HOHHOT, June 5 (Xinhua) -- A forest fire that broke out in north China's Inner Mongolia Autonomous Region continued for the fifth day Tuesday, local fire authorities said.

The fire started in the Hanma National Nature Reserve in the northern area of the Greater Hinggan Mountains Friday and spread to neighboring Heilongjiang by Sunday afternoon.

More than 4,300 firefighters and forest police are battling the fire, while artificial precipitation has also been planned to put out the fire.

High temperatures and drought in the region have increased the risk of forest fires in the mountains.