Officials in India's Maharashtra state have begun sealing off an entire town where bird flu has been discovered.
Sales of chicken have dropped sharply
No-one will be allowed in or out of Navapur, which has a population of nearly 30,000, or 19 nearby villages.
The measures come after reports that blood samples from people in hospital have tested positive for bird flu. Health officials deny the reports.
Hundreds of thousands of birds are being culled after deadly H5N1 bird flu was found in Navapur last week.
Health Ministry officials say tests on 90 of 95 people for bird flu have proved negative.
The other five samples, taken from 12 people who have been quarantined with flu-like symptoms in Maharashtra, are being tested further. Results are expected on Thursday.
"We do not rule out the possibility of humans being affected, and it is a distinct possibility," Health Secretary PK Hota told reporters in Delhi.
'Safe to eat'
Chicken and eggs are off the menu in most parts of India.
The country's poultry industry, one of the world's largest, has already been hit with massive losses.
On Wednesday, the Indian parliament banned poultry products from its cafeterias.
Major airlines, the country's railway service and the army have all taken similar steps.
"We are not cooking poultry dishes but have put extra mutton and fish dishes on the menu," a parliamentary chef told the AFP news agency.
But other government officials are reassuring people that chicken and eggs are safe to eat if cooked properly.
Health officials served chicken dishes and ate them in front of the media at a scheduled news briefing on bird flu in the capital, Delhi, on Tuesday.
Teams of health workers have killed hundreds of thousands of birds around the town of Navapur.
Reports say the focus has now shifted to cleaning up the area after the mass slaughter.
But poultry traders and farmers say they are struggling after a sharp drop in sales.
One trader in the city of Mumbai (Bombay) distributed 2,000 chickens for free on Wednesday in an attempt to dispel fear.
Poultry exporters say they have already suffered more than $45m in losses and say exports have been badly hit, particularly to the Middle East.
The H5N1 virus does not pose a large-scale threat to humans, as it cannot pass easily from one person to another.
Experts, however, fear the virus could mutate to gain this ability, and in its new form trigger a flu pandemic, potentially putting millions of human lives at risk.