Chinese authorities say they are mobilising resources along the eastern seaboard to combat a new strain of bird flu that is so far known to have killed six people, including four in the city of Shanghai.
All birds at the Huhuai poultry market in western Shanghai are being slaughtered after the new strain, H7N9, was detected in pigeons sold there.
From China's vast population there have been just 14 reported infections, but the cases are now spreading around the east of the country and numbers will almost certainly grow, especially as health authorities are looking more closely for the disease, the BBC reports.
Although the virus is a type of avian flu, it doesn't appear to make birds sick, which in turn makes it harder to track down the sources of the virus.
It is not yet known how people are catching the disease, although the World Health Organization says there is currently no evidence of human-to-human transmission.
The confirmed infections have also been reported in Zhejiang province.
The Chinese government has stepped up its disease surveillance and advised people to maintain good personal hygiene, including frequent hand-washing and avoiding direct contact with sick or dead animals.
The Centers for Disease Control and Prevention in the United States says that it is developing a vaccine in case it is needed.