The seven Malaysians, including five children aged between two and 12, all had respiratory problems and test results would be available within a day, health minister Chua Soi Lek said on Wednesday.
Malaysia took its search for birds stricken with avian flu to the heart of its capital as speculation grew that fighting cocks, smuggled into the country, could have brought the virus.
The minister said all seven residents lived within 300 metres of the affected area on the edge of the capital, Kuala Lumpur, where 40 infected chickens died last week in the country's first outbreak in more than a year.
"Those warded are the ones exposed to the chickens," he said, using a common term for admission to hospital.
Kamaruddin Mohamad Isa, the director for disease control in the Veterinary Services Department, announced a 10km radius observation zone around four villages, encompassing Kuala Lumpur's upmarket neighbourhoods of Bangsar and Sri Hartamas, and the city centre area, including the Petronas Twin Towers.
Bird flu has killed more than 90 people since 2003. Despite its rapid march around the globe, it remains hard for people to catch. But if it mutates, a pandemic could bring economic chaos and overwhelm health services.
Migratory birds are thought to be at least one way the disease is being carried and more than 30 countries have reported cases since 2003, seven of them recording human infections.
On Tuesday, Malaysia and Hungary joined 13 other countries this month to report outbreaks of the H5N1 virus in birds but none of the newly affected nations has reported human cases.
Alarm is growing at the sudden resurgence of the virus in recent weeks as it spreads rapidly across Europe, into Africa and now India, where hundreds of millions of people live in rural areas side-by-side with livestock and domestic fowl.
Experts fear it is just a matter of time before the virus mutates and spreads easily among people, triggering a pandemic.
The Indian cases are said to have
had close contact with poultry
Indian health workers, some wringing the necks of chickens, others using poison, are carrying out a mass cull of birds to try to stamp out the country's first outbreak of the virus.
The dozen quarantined people have been placed in an isolation ward at a hospital in Navapur town in the western state of Maharashtra, where H5N1 was found in poultry on Saturday.
Those quarantined either had flu-like symptoms or were kept there as a precautionary measure. Blood samples from dozens of other people were also being tested, Indian officials said.
"The initial results are expected today (Wednesday) evening," Vijay Satbir Singh, Maharashtra's top health official, told Reuters. "We are keeping our fingers crossed."
Adding to fears, there were reports of more poultry dying beyond Maharashtra, where the sudden deaths of 50,000 birds heralded the initial outbreak.
Culling under way
Indian health workers wearing blue overalls, anti-viral masks and goggles have so far culled about 400,000 birds in Maharashtra, of which Mumbai is the capital.
But a report in the Times of India newspaper said the culling process suffered from defects because many birds, buried alive in shallow pits, were re-emerging. TP Doke, the state health director, denied knowledge of the chickens being buried alive.
In Indonesia, where the virus is endemic in poultry, a Health Ministry official said a 27-year-old woman who lived in the capital had died of bird flu, according to local hospital tests. If confirmed by the World Health Organisation, the woman would be the 20th Indonesian to die from avian flu.
The southern Russian region of Dagestan on Wednesday declared a quarantine in 17 villages after the H5N1 bird flu strain was detected in three poultry farms, officials said.
The H5N1 virus is endemic in
poultry in Indonesia
The chief veterinary official, Zaidin Dzhambulatov, said it was forbidden to transport fowl and poultry products from these villages. He added that strict restrictions on access to 10 poultry farms were also in force.
Around 500,000 chickens have been destroyed or died in Dagestan this month.
An outbreak of bird flu is virtually unavoidable in Afghanistan, and the local government and donor nations have been slow in acting to prevent the deadly disease from spreading to the country, a UN official said on Wednesday.
Migratory birds that can carry the illness are already arriving in Afghanistan, said Serge Verniau, the representative for the UN Food and Agriculture Organisation in Afghanistan.
"With cases of the deadly disease detected in Iran and India, Afghanistan is practically surrounded," Verniau said. "Today, we can say an outbreak of the disease among birds in Afghanistan is virtually unavoidable."
Ban on imports
Thailand has imposed a ban on poultry imports from European countries hit by the bird flu epidemic, a senior livestock official said on Wednesday.
The ban will last 90 days, but could "be lifted earlier if concerned countries can manage to curtail the disease before that", said Nirandorn Auengtrakulsuk, director of the livestock disease control division.
The ban applies to Bulgaria, Romania, Germany, France, Italy, Austria and Slovenia, he said.
Thailand has imposed a ban on
poultry imports Europe
In Brussels, EU animal health experts considered requests from France and the Netherlands, Europe's biggest poultry producers, to be allowed to vaccinate millions of birds against avian influenza. Talks on the request are continuing.
Hungary said on Tuesday that tests showed the virus in three dead swans found last week, while Croatia also confirmed H5N1 had been found in a dead swan on an island in the Adriatic.
In Europe, officials urged people to carry on eating poultry meat after a string of outbreaks in birds. The WHO says thoroughly cooked poultry meat and eggs are safe to eat but that assurance has failed to calm consumers in many countries.