HOHHOT, June 27 (Xinhua) -- Around 40 percent of north China's Inner Mongolia Autonomous Region is suffering from a persistent drought, causing over 600 million yuan (about 91 million U.S. dollars) in direct economic losses.

According to the regional department of agriculture and animal husbandry, nearly 37 million hectares of grassland and over 35 million livestock had been affected by Wednesday.

The recent drought also caused a rat plague, as the rodents are more adaptable to dry weather. The plague has threatened more than 4 million hectares of grassland in the region.

In some areas, the rats have ravaged the grassland, eating roots and damaging prairies with their ferocious underground digging.

According to the regional weather bureau, since mid-June Inner Mongolia has seen 25 percent less rainfall and is around 1 degree Celsius higher in temperature than the same period in previous years.

The local government has sent 700,000 tonnes of forage grass to drought-hit areas and offered subsidies to reduce the losses of herdsmen.