China's Health Minister Gao Qiang on Monday ordered health departments across the country to act quickly in the prevention and control of human infection of bird flu.

Addressing a national televised conference, Gao ordered them to strengthen work at three key links, namely monitoring, control and treatment, stressing that early action is crucial in all of them.

"The health departments should work synchronously with the agricultural departments once they learn about the outbreak of an epidemic among animals," said Gao.

He said health personnel should arrive at the spot, conduct an investigation and proceed to handle the epidemic at the same time together with personnel of the agricultural departments.

He ordered the health departments to maintain an efficient information sharing mechanism with relevant departments, including civil aviation and transportation departments, to ensure quick actions.

Gao said in case any humans are infected with bird flu, the health personnel should give play to traditional Chinese medicines while treating them.

"There should also be an expert panel to provide technical support," he said.

Gao also stressed the importance of promoting publicity of epidemic prevention knowledge and actively strengthening international and regional cooperation.

The ministry has invited the World Health Organization to support the ongoing investigation of three cases in Hunan Province currently diagnosed as "pneumonia of unknown causes."

"After conducting comprehensive analysis, experts said althoughthe three cases are diagnosed as pneumonia of unknown causes at present, the possibility of human infection of the highly pathogenic H5N1 strain of bird flu cannot be ruled out," a spokesman for the ministry said on Sunday.

A dialogue is underway between China and the WHO to determine what this assistance should be, according to WHO's Beijing Office on Monday.