Thailand has suffered an outbreak of the deadly H5N1 strain of bird flu, its first for six months.
Indonesia has been hit badly with four deaths this year so far
The virus was confirmed following the deaths of around 100 ducks in the northern Phitsanulok province.
Meanwhile, neighbouring Vietnam says bird flu has reached a seventh province in the Mekong Delta region.
Health officials across Asia are on alert as a growing number of countries have reported cases in both birds and humans in recent weeks.
Four people have died from the virus in Indonesia this year, while China has confirmed a human infection.
Japan is culling 12,000 birds after an outbreak at a farm south-west of Tokyo at the weekend. It is not clear if the virus is the deadly H5N1 strain.
As a result of the outbreak, Hong Kong says it is banning all imports of poultry from Japan with immediate effect.
Hong Kong itself is carrying out further tests after initial tests on a dead Crested Goshawk showed it carried the H5 strain of the virus.
Bird flu has claimed more than 150 lives since it began ravaging Asian poultry farms in late 2003.
There had been a noticeable drop in the number of cases in recent months as a result of improved surveillance and vaccination programmes across the region.
However, the virus is more active during colder, winter months.
Hans Troedsson, of the World Health Organization (WHO) in Vietnam, said there was still a danger the virus could mutate into a form that is easily passed between humans.