Hong Kong  - Hong Kong officials Saturday banned all poultry imports from China and began killing thousands of chickens as bird flu was detected at a city market.

All poultry in the city may be slaughtered in a repeat of the 1990 culls if cases are found in other markets in the former British colony, officials said.

The outbreak, the first in Hong Kong in recent years, was discovered at a livestock market in the city's Shamshuipo district, the government said.

The H5N1 bird flu virus was found on swabs on chicken faeces from the market in Po On Road which was Saturday declared an infected area and sealed off to the public.

Workers in protective suits and masks began culling around 2,700 chickens in the market as tests were carried out on poultry at other markets in the city of 6.9 million to see if the outbreak had spread.

Health Secretary York Chow told a news conference Saturday that all live chicken imports from mainland China, the main source of poultry in the densely populated city, had been immediately banned.

He said that all chickens in the Shamshuipo market had been slaughtered and that the government would killing all chickens if more cases were discovered.

A government spokesman said: "The incident has been reported to mainland (China) authorities and quarantine units have been asked to pay special attention to the registered farms supplying poultry to Hong Kong.

"Although no human avian flu cases have been reported so far, the Department of Health and the Hospital Authority will enhance prevention work."

Hong Kong was home to the first modern case of bird flu to jump the species barrier and infect humans in 1997 when the H5N1 virus killed six and infected 12 other people.

Since then, thanks largely to stringent checks and mass culls when any cases are discovered, there have been no further cases of humans infected by bird flu in Hong Kong. (dpa)