The drought that has struck five provinces in Southwest China has become increasingly worse, leaving at least 11 million people short of water and endangering crop yields of at least 3.8 million hectares, authorities have warned.

Guaranteeing the supply of drinking water will be the highest priority for drought relief efforts in Yunnan, Guizhou, Guangxi, Chongqing and Sichuan, as the drought is expected to last until mid-March, the Office of State Flood Control and Drought Relief Headquarters said on Tuesday.

The dry spell, which began in September, has left more than 15 million people and 9 million livestock without adequate water supplies.

It has also affected 4.4 million hectares of farmland across the country, according to statistics.

There is also little relief in sight. With hardly any rain expected, the dry weather and high temperatures are expected to continue for the next 10 days in affected regions, especially Yunnan, Sichuan and Guizhou, national weather forecasters said.

In an effort to create rain, the China Meteorological Administration (CMA) said that weather bureaus in the affected regions are ready to "bomb clouds" with 2,116 doses of silver iodide, a compound used in cloud seeding, for which 2 million yuan ($294,000) has been allocated.

The average temperature in Yunnan from September 2009 to February this year was 22.7 C, which is 2.2 C higher than usual and a record high since 1952, according to statistics released by the CMA.

"The duration, scope and impact of the drought are rare," said Chen Zhenlin, spokesman for the CMA.

Over the past year, there was a short rainy season in Yunnan, with only 31 days of rain, a year-on-year decrease of 31 days, another historic record since 1952, according to statistics from the CMA.

The high temperatures and shortage of rain have caused some reservoirs to dry up, leaving millions of people short of drinking water.

Lijiagou reservoir in Rongchang county, Chongqing, has run dry and cannot supply water for the 20,000 residents in the area, local media reported.

Since October 2009, water has been available for residents near the reservoir for only five hours a day.

As a result, the local government has had to arrange for water to be transported from the Laixihe River to help residents in the area cope with the shortage, Zhang Zhengbin, director of the Fuchang street community office, told the Chongqing Economic Times newspaper.

According to the latest figures released by the Chongqing municipal flood control and drought relief office, the drought has left 590,000 people and 370,000 livestock suffering from a shortage of adequate drinking water and affected 175,000 hectares of farmland across the municipality.