Hong Kong - Hong Kong officials on Wednesday ordered the culling of all poultry in markets after confirmation that the deadly bird flu virus had been found in four markets.

The government said tests carried out on chicken faeces at four markets throughout the territory had shown positive results for the H5N1 virus which has infected 383 and killed 241 people worldwide since 2003, according to the World Health Organization.

Up to 3,000 birds are expected to be slaughtered, however birds in local farms will not be affected.

The discovery follows the culling of almost 3,000 chickens at the weekend after the virus was discovered at a city market in Po On Road.

The mass culling is a grim reminder to Hong Kong of 1997 when all poultry were slaughtered when the territory experienced the first modern case of the bird flu virus jumping the species barrier to infect humans.

On that occasion the move came too late to avoid human fatalities and six of the 18 people infected died.

Since, 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.

However, the new discovery highlights the difficulties in protecting Hong Kong completely from the virus, which is speculated to have been carried over the border from China in smuggled chickens.

Deputy director of food and environmental hygiene Alice Lau said that so far the virus had not been found in any dead chicken and there had been no human infections

"Of course we cannot be complacent and that is why we are taking this decisive measure to close all retail outlets and cull all remaining poultry," she said. (dpa)