Hong Kong health workers slaughtered 2,700 poultry on Saturday after excrement samples taken from one of the city’s markets tested positive for the deadly strain of H5N1 avian influenza virus.

Secretary for Food and Health York Chow said all birds will be slaughtered if “we find another positive detection in another market,” the Associated Press reports.

The samples were collected June 3 from three vendors in the market in the Sham Shui Po residential district. After testing positive for bid flu, the market was declared an infected area and all sales of live poultry there were suspended.

All the city’s 64 poultry markets will be inspected for bird flu virus, Chow said.

It is not the first time Hong Kong confronts with the disease. Wild birds tested positive for avian influenza virus in 2007 as well. However, this is the first time when health officials detected H5N1 in a Hong Kong poultry market, which “is a bit unusual,” Yi Guan, a professor of microbiology at Hong Kong University said.

The presence of bird flu in Hong Kong made the authorities to immediately ban all live chicken imports from mainland China, the main source of poultry in the densely populated city.

The bird flu virus began ravaging Asian poultry stocks in late 2003. According to the World Health Organization, there have been 382 human cases worldwide since 2003, 241 of them fatal. Indonesia is the hardest hit regions of all, with 108 of the deaths and is seen by health experts as a potential hotspot for a pandemic.

Scientists have long warned that the H5N1 strain of bird flu virus could mutate into a form that spreads easily among humans, leading to a pandemic that would kill millions. So far, most human cases have been linked to contact with infected birds.