A local health authority on Wednesday attributed pollution that sickened more than 2,600 people in north China's Inner Mongolia Autonomous Region to heavy rain that caused contaminants to seep into the water supply.

Gao Xihua, vice secretary general of the Chifeng City Committee of the Communist Party of China, said Wednesday that tests had shown an excessively high count of bacteria, including coliforms and salmonella, in samples taken from the supply.

"The rainwater, along with dirt, are major causes of the water pollution," he said.

Gao said 2,622 people had sought medicine for gastrointestinal illnesses after tap water supply was contaminated about 5:30 p.m..

In the 24 hours up to 5:30 p.m. Tuesday, 1,112 new cases were reported. By Tuesday night, 59 people had been hospitalized for medical observation, a spokesman with the city's health department said.

The patients, from eight downtown communities in Chifeng, complained of fever, diarrhea, stomach aches and vomiting after drinking water from taps in their homes Saturday and Sunday.

The local government started offering free medication to all victims on Monday.

On Monday night, a government official blamed the pollution on the heavy rainfall of July 23, which caused water from a nearby lake to flow into the supply system.

The contaminated system provides tap water for Chifeng's "new city center", a 17-square km area with a population of 58,000, said Zheng Fengjun, an official of Yulong Community.

(Xinhua News Agency July 29, 2009)