A second big fire broke out in China's largest forest in the Greater Hinggan Mountains on the same day a cross-border fire from Russia was extinguished.

The fire broke out at 12:15 pm on Tuesday in the Beidahe forest in the Inner Mongolia autonomous region. More than 8,300 firefighters are working to extinguish the blaze, according to regional fire authorities.

By press time, the fire had engulfed about 50 square kilometers of forest. The firefighters - 2,590 of whom are armed police officers - and 12 helicopters have been sent.