A plague of rats is threatening more than 10 million hectares of grassland in north China's Inner Mongolia Autonomous Region and northwestern Xinjiang Uygur Autonomous Region, local authorities said Saturday.

In Inner Mongolia, 5.82 million hectares of grazing land have been overwhelmed by the burrowing rodents, said Zhang Zhuoran from the Inner Mongolia Autonomous Regional Department of Agriculture and Animal Husbandry.

In worst-hit Urad Prairie in Bayannur League, burrows pocked the bare, yellowish-brown earth after rats chewed through a large areas of grass.

Dry weather is to blame for the rat plague, Zhang said.

In Xinjiang, 5.58 million hectares of grassland have been affected by the rodents.

In addition, pests and poisonous weeds are threatening 9.59 million hectares of grazing land, said Mu Chen from the Xinjiang grasshoppers and prairie rats control headquarters.

Authorities in the two regions are combating the rat plague through poison sprays, sometimes using airplanes.