China's Health Ministry on Saturday called for heightened measures against the possible spread of bird flu virus after a woman in central China died from the disease on June 3.

The ministry urged health authorities at all levels to increase prevention and control measures on respiratory diseases as the country's southern areas are entering into the peak flu season.

Health authorities at all levels, especially in Shanghai and Guangzhou, host cities respectively for the 2010 World Expo and the Asian Games, were asked to formulate emergency plans to cope with the possible spread of the disease, according to a notice posted on the ministry website.

Health authorities at all levels should report and respond quickly to unidentifiable pneumonia, it said, adding they should also prepare medical equipment and pharmaceuticals to cope with possible outbreaks of respiratory diseases, such as bird flu.

Health authorities in Shanghai, Guangzhou, quake-hit Yushu in Qinghai Province and southern provinces plagued by floods were also asked to coordinate the assistance of experts to take effective measures on disease prevention and control.