More than 8,300 firefighters have been mobilized to fight a forest fire that broke out in the Inner Mongolia autonomous region at around midday on Tuesday, authorities said on Wednesday.

The wildfire, which broke out in Beidahe forest in the Greater Hinggan Mountains, had engulfed about 5,000 hectares by Wednesday morning, according to the regional forest fire prevention headquarters.

Dry vegetation, strong winds and temperatures of up to 29 C had made it difficult to extinguish the blaze, the headquarters said.

The State Forest Fire Prevention Headquarters dispatched 12 firefighting airplanes, while preparations for precipitation enhancement have been completed to aid efforts in bringing the flames under control.

The cause of the blaze is unknown, but higher than average temperatures this spring have increased the risk of fires.

A fire in another forest in the area raged for three days and spread across the border into Russia before being put out on Tuesday.