KOLKATA (AFP) - An Indian state said it had brought the country's worst ever bird flu outbreak under control on Saturday, just as neighbouring Bangladesh reported the virus was spreading.

The deadly H5N1 strain of bird flu had been detected in 13 of 19 districts in the eastern Indian state of West Bengal since the outbreak began in mid-January.

The state's Animal Resource Development Minister Anisur Rahaman told AFP that health workers expected to complete the culling of three million poultry by late Saturday.

"We have so far culled nearly 2.9 million poultry since January 14," when the outbreak -- India's third and worst -- was confirmed, Rahaman said.

He added that the "next plan is to disinfect thousands of backyard poultry yards where culling has been done."

The state government was taking all possible steps to stop the spread of bird flu to humans, he said.

Humans typically catch bird flu by coming into direct contact with infected poultry, but experts fear the H5N1 strain may mutate into a form easily transmissible between people.

"All culling workers have been asked to stay for at least 10 days in hospital to take the full course of (antiviral drug) Tamiflu and burn clothes worn during culling," Rahaman said.

At least 700 were already in hospital taking Tamiflu, recommended by the World Health Organisation as a first line of defence against the virus, Rahaman said.

No cases of humans catching bird flu have yet been reported in India or Bangladesh. But in Indonesia on Friday, a 31-year-old woman died of the virus, bringing the toll to 102 in the nation worst hit by the illness.

"If anyone has a cold or fever we are sending his blood sample for tests," Rahaman added.

Once the culling operations were completed, more people would be admitted to hospital to take Tamiflu under supervision, he said.

Neighbouring Assam state ordered a cull in villages bordering West Bengal following suspicious poultry deaths. And Haryana, next to capital New Delhi, has sent dead bird samples for testing.

Meanwhile, Bangladesh slaughtered tens of thousands of chickens on Saturday as four more districts reported detecting bird flu.

"The disease is spreading," livestock department chief Sunil Chandra Ghosh said, insisting authorities had the situation under control.

The H5N1 strain has now spread to 34 out of Bangladesh's 64 districts, forcing police and livestock officials to slaughter 35,000 chickens in the past three days alone, officials said.

The government in Dhaka ordered major hospitals to set up isolation units to treat bird flu suspects.

"We've taken blood samples of 837 people and none have been found positive. We've also confined several people in their homes, while more than a thousand are under our watch," government spokesman Mahmudur Rahman said.

Health officials investigating bird flu cases called the situation "alarming" and getting worse every day.

"There's a huge lack of awareness in the countryside. People are throwing away dead chickens to open fields, canals and ponds. Crows which have eaten the cadavers are dying by the hundreds," a health officer told AFP.

The disease was first detected in Bangladesh last February near the capital Dhaka. It was almost dormant by late 2007, but made a forceful comeback in January this year.