HARBIN -- Lack of rainwater, coupled with falling river levels, is endangering more than 50 percent of grain fields in northeast China's Heilongjiang Province, China's largest grain production base, said drought relief officials here on Friday.

Hou Baijun, deputy commander of the provincial drought relief headquarters, said that 6 million hectares of grain fields, or 53 percent of the province's total, has been dry since mid-May.

The average river level in the agricultural plain area was 0.39-1.96 meters lower than that of a normal year, which was considered abnormal, he said.

He said the provincial government has allocated 460 million yuan of drought relief fund this month, which has helped dig more than 30,000 wells for irrigation.

"If there is no sufficient rainfall to moisten the land before June 10, this year's grain production would be harmed," he said.

The provincial meteorological department forecast there will be a weak cold air front coming through the province during the weekend. The department has prepared to use weather modification means to enhance the rain effect.

Heilongjiang has one tenth of China's grain production areas. Its grain output, mainly rice and corn, topped 160 billion kg last year.

The province launched emergency response mechanisms on Thursday to cope with drought. Ji Bingxuan, party chief of Heilongjiang urged local officials to take lead in the fight against drought, and transport and power departments give their priority work to ensure the drought relief work.