Livestock officials slaughtered more than 27,000 chickens and ducks in northern Bangladesh after bird flu was confirmed at a poultry farm near the border with India, a report said Friday.

Officials in India's West Bengal state, which borders Bangladesh, have been struggling to contain that country's worst-ever outbreak of the virulent H5N1 bird flu virus.

Several hundred chickens died at the poultry farm in Dinajpur district, 170 miles north of Dhaka, and laboratory tests confirmed that the H5N1 virus was responsible, the United News of Bangladesh news agency reported.

Local livestock official Sydur Rahman said more than 27,000 chickens and ducks were killed and more than 60,000 eggs were destroyed on Thursday and Friday in an attempt to halt the spread of the virus, the agency said.

Local officials were not immediately available for comment Friday.

On Thursday, the government warned the Department of Livestock that more precautions were needed to prevent the disease from spreading.

Experts say any widespread outbreak could be disastrous for Bangladesh because of its dense population and poorly equipped public health care system.

Bird flu has been confirmed in at least 30 of Bangladesh's 64 districts and has struck more than 97 farms since it was first detected in February last year. More than 350,000 birds have been slaughtered, according to the Ministry of Fisheries and Livestock.

No cases of human infection have been reported.

Bird Flu Death Toll

While the virus remains hard for people to catch, experts worry it could mutate into a form that passes easily among people, igniting a flu pandemic. Although a few are now calling the risk "overestimated," recent developments raise new concerns:

— Four people died this week in Indonesia — where the virus was first reported in humans in 2005 bringing the country's toll beyond the 100 mark.

— India is battling its worst-ever poultry outbreak. No human cases have been reported, but more than 129,000 poultry have died from bird flu in West Bengal state in recent weeks and nearly 2.5 million at-risk birds have been slaughtered, according to Animal Resource Development Minister Anisur Rahaman. Officials fear the disease could reach crowded Calcutta and its 14 million people.

— Pakistan and Myanmar both reported their first human infections in December. That brings to 14 the number of countries where the virus has jumped from poultry to people.

The H5N1 bird flu virus still has killed relatively few people since it began destroying Asian chickens and ducks in late 2003. More than 220 people have died, nearly all from close contact with infected birds. About 60 percent who catch the virus die.

The most recent death in Vietnam — one of the countries most successful at quashing the virus — offers a typical illustration of how people get infected. A man died after butchering and cooking geese and chickens that had died at his backyard farm. Tests showed they had the H5N1 virus. The victim was Vietnam's 48th since 2003.