Hong Kong officials say they plan to slaughter all live poultry in the territory's street markets after detecting the dangerous H5N1 bird flu virus.

Agriculture, Fisheries and Conservation Director Cheung Siu-hing says tests returned Wednesday showed birds infected in four markets.

Cheung did not say how many birds would be killed. She says the virus has not been detected in samples from local chicken farms and distribution centers.

Health workers killed 2,700 poultry on Saturday in a market after routine testing showed five chickens were infected with the virus.

The government also temporarily banned supplies from all live poultry from mainland China and local farms.