BEIJING - China's Ministry of Health has urged local governments to be on alert for SARS and human cases of bird flu and to strengthen prevention against epidemics as winter approaches.

Severe Acute Respiratory Syndrome first emerged in China's southern Guangdong province, and the country is at the center of the fight against the H5N1 bird flu virus, with dozens of animal outbreaks and 21 human cases since 2003.

"Experts believe that currently China has already entered the high season for respiratory disease," the ministry said in a statement on its Web site (www.moh.gov.cn) on Tuesday.

"The health ministry demands that all localities strengthen supervision and reporting of cases of pneumonia where the cause is unclear, human cases of bird flu, ordinary influenza cases and SARS," it said.

Local authorities must "immediately report outbreaks and adopt measures to prevent and control epidemics," the statement said.

Experts say management of outbreaks has improved, but the government has acknowledged a lack of administrative capacity and a willingness among local officials to disclose information.