DHAKA, May 11 (Reuters) - Some 10,000 chickens were culled in Bangladesh over the last two days as bird flu spread despite veterinary and health workers"e; efforts to contain it, officials said on Friday.

"Laboratory tests suggest that H5N1 virus has infected a farm at a village near Nilphamari district town 400 km (250 miles) northwest of the capital Dhaka," said Abdul Motalib, an official of the Fisheries and Livestock ministry.

Some 142,000 chickens have been culled and 1.4 million eggs destroyed in 53 farms in 11 districts since the virus was first detected in six farms at Savar near Dhaka on March 22, officials said.

There have been no reported cases of human infection.

More than 1,000 people engaged in culling had been given a dose of Oseflu, a local version of Tamiflu, Motalib said.

The virus is known to have infected nearly 300 people in 12 countries since 2003, killing more than half of them.

"Veterinary and health workers are working hard to contain the virus, which however continued to sneak into new farms," another ministry official said.

Authorities have pledged to pay 70 taka (nearly $1) for each culled bird, and money to restart their businesses.

The country has 125,000 small and large poultry firms producing 250 million broilers and six billion eggs annually. About four million Bangladeshis are directly or indirectly associated with poultry farming.

After an initial slump following the outbreak of the virus, the poultry business was recovering as people resumed consuming chickens and eggs following a government campaign.

Health officials said there is no fear of infection if chicken and eggs are properly cooked.