Authorities warn that the human threat from bird flu has not gone away
More than 370,000 chickens have been culled in China's eastern province of Jiangsu after an outbreak of the H5N1 strain of bird flu, say officials.
The outbreak is thought to be the first in mainland China since June.
Meanwhile, a man has reportedly contracted the virus in Cambodia, while Taiwan is investigating suspected infection among birds.
The death of a teenage girl from H5N1 was announced in Egypt on Tuesday, and a bird cull is also under way in India.
More than 200 people in a dozen countries have died of the virus since it resurfaced in Asia in 2003, say global health authorities.
Experts fear that the virus could mutate into one that is easily transmissible from human to human.
Migrating birds blamed
China's Ministry of Agriculture said it received notification that the H5N1 virus had been found in two areas of Jiangsu on Monday.
The usual precautions have been imposed: birds have been slaughtered in the surrounding area, farms quarantined and disinfected, and the transport of fowl banned.
But no information has been released about the scale of the outbreak - how many birds were found to be carrying the H5N1 strain of the virus and how many of them died.
Officials say they think migrating birds might have been the source of the disease.
They are currently testing samples of the virus to check it has not mutated into a form that would pose a risk to human health, reports the BBC's Chris Hogg in Shanghai.
China is among a number of countries experiencing a return of the virus this season:
• Authorities in the Indian state of West Bengal are implementing a cull after tests on poultry from two villages yielded positive results
• In Cambodia, another cull is under way after the World Health Organisation (WHO) and government confirmed a young man had the virus, according to Reuters news agency
• Authorities in Taiwan say they are investigating the cause of the sudden death of poulty in Luzhu, Kaohsiung county, Reuters says
• Earlier in the week, Egyptian authorities announced the death of a 16-year-old girl from the virus
• The discovery of infected birds in Hong Kong last week sparked a cull of more than 80,000 birds
The WHO recently warned governments in Asia not to let down their guard against bird flu.
Some experts fear that because the virus has not yet mutated into a form that could spread easily among humans, the fight against bird flu is seen as less of a priority than before.
Countries like China - with huge densely populated cities and in many places only basic healthcare and veterinary services - are thought to be particularly vulnerable should the virus become more deadly, says our correspondent Chris Hogg.