HARBIN, June 6 (Xinhua) -- A forest fire that spread from north China's Inner Mongolia Autonomous Region to neighbouring Heilongjiang Province is finally under control, local fire authorities said Wednesday.

As of 10 p.m. Wednesday, the fire, which has burnt around 2,000 hectares of forest in a nature reserve in Heilongjiang, was under control after the province mobilized more than 4,600 fire fighters, 31 helicopters, as well as large fire fighting equipment to put out the fire.

The fire broke out in Hanma National Nature Reserve in the northern area of the Greater Hinggan Mountains in Inner Mongolia on Friday, and had spread to Heilongjiang by Sunday afternoon.

The fire in Inner Mongolia was finally put out at around 10 a.m. Wednesday. It is believed to have been caused by lightning strikes.