The first case of bird flu has appeared in the United States.
More than 12,000 chickens have been quarantined in the state of Delaware, and are due to be destroyed.
However, health officials say the strain of the disease, known as H7, is different from the H5N1 strain that has killed 18 people in Thailand and Vietnam, and has led to the slaughter of millions of chickens across Asia.
Meanwhile, China has confirmed three more cases of the disease, bring the total of confirmed bird flu cases in the country to 13.
