Indian health officials have begun a mass slaughter of poultry in the eastern state of West Bengal, one day after authorities confirmed an outbreak of deadly bird flu in the area.

Local officials say at least 3,500 birds have died of the H5N1 strain of the virus in West Bengal's Malda district.

Authorities have banned the transport of poultry from the affected areas and will kill at least 15,000 chickens and ducks starting Tuesday in an effort to contain the virus.

Health officials cull chickens suspected to be infected with bird flu virus at a farm in Gawahati, India, 11 Dec 2008

Hundreds of thousands of poultry are already being culled in the northeastern state of Assam, where bird flu was detected late last month.

Health workers in Assam are monitoring at least 100 people who have shown signs of the virus, but officials have not confirmed a human case.

Authorities have also banned the sale and export of poultry products in Assam. They say six people have been arrested for smuggling chickens from Guwahati, Assam's main city.

The World Health Organization says bird flu has killed at least 246 people worldwide since it resurfaced in Asia five years ago, but no human cases have been reported in India. 

Some information for this report was provided by AP and Reuters.