Preliminary testing of the carcasses of a black-headed gull and a peregrine falcon found in Hong Kong have returned a positive result for the H5 avian influenza virus, a spokesman for the city's Agriculture, Fisheries and Conservation Department (AFCD) said Tuesday, adding that further confirmatory tests are being conducted. According to the spokesman, the black-headed gull was collected at Castle Peak Power Station Plant B, Tuen Mun on March 2, while the peregrine falcon was found at Kam Kwai House, Kam Fung Court, Ma On Shan on March 3. The black-headed gull is a common winter visitor to Hong Kong, while the peregrine falcon is a rare winter visitor. The spokesman said cleansing and disinfection have been stepped up at the venues, adding that there are no poultry farms within three km of where the dead birds were found. In view of the cases, the AFCD has phoned poultry farmers to remind them to strengthen precautionary and biosecurity measures against avian influenza. Letters have been issued to farmers, pet bird shop owners and licence holders of pet poultry and racing pigeons reminding them that proper precautions must be taken. The spokesman also cautioned that people should avoid personal contact with wild birds and live poultry and their droppings. Furthermore, all relevant government departments will continue to be highly vigilant and strictly enforce preventive measures against avian influenza.