Guwahati (IANS): The Assam government has sounded a health alert and banned the sale of poultry following the spread of the deadly bird flu virus to newer areas, officials here said Wednesday.

"Samples of dead birds tested positive for avian influenza in a number of villages in Kamrup district," district magistrate R.C. Jain said.

"We shall be carrying out culling of birds in 11 villages from Thursday," he added.

There was an outbreak of bird flu last week in the Hajo area of Kamrup district, about 35 km from Assam's main city of Guwahati.

"An estimated 60,000 birds were ordered to be killed in 48 villages within a five kilometre radius from where avian influenza was reported," Jain said.

The culling operations in the 48 villages are almost complete. The poultry targeted includes ducks and chickens.

"It is a matter of concern with the virus now spreading to new areas and hence a maximum health alert has been sounded. Teams of doctors and paramedics are taking precautionary measures so that humans are not affected," said Parthajyoti Gogoi, a central health ministry official.

The central health ministry last week confirmed outbreak of bird flu after laboratory tests found strains of the deadly H5N1 avian influenza. More than 600 birds have died in Kamrup district in the past one week.

Assam's veterinary and animal husbandry department has sounded an alert and maintaining strict surveillance on farms in the state with veterinarians carrying out checks on all poultry.

A central health ministry team is also assisting the local authorities in the culling operations.

The World Health Organization (WHO) fears that the H5N1 strain could mutate into a form easily transmitted between humans and spark a deadly pandemic.