Chinese officials say they have asked the World Health Organization to help determine if three people have contracted the deadly H5N1 strain of bird flu.
China's Xinhua news agency reports the three, one of whom has died, lived in central Hunan province, where an outbreak of the virus recently killed thousands of birds.
China has reported several mass outbreaks in bird populations across the country in recent weeks.
On Sunday, in Liaoning province which borders North Korea, health workers and police are battling another outbreak, slaughtering hundreds of thousands of birds.
North Korea's official news agency says officials there are aware of the bird flu threat and have announced measures to prevent the spread of the disease.