The Central government on Tuesday confirmed an outbreak of bird flu in two districts of West Bengal, a day after the state government declared an alert in the area.

"Samples have been tested positive," a government official said.

The samples of the dead birds had been sent to High Security Animal Disease Laboratory in Bhopal to find out whether the death of poultry was due to Avian Influenza, commonly known as Bird Flu [Images].

"It is a localised occurrence of bird flu in the two districts of West Bengal namely Birbhum and South Dinajpur," the official said.

The Centre as a precautionary measure had restricted trade and movement of poultry birds in these two districts.

The Health Ministry had on Monday dispatched a team from the National Institute of Communicable Diseases to West Bengal.

The parallel samples have been sent to the National Institute of Virology, Pune.

Meanwhile in West Bengal, the Birbhum district administration has dispatched 50 special teams to help people dispose of dead chickens in Rampurhat sub-division where a bird alert has been sounded.

An emergency meeting of all the Block Development Officers of Rampurhat Sub-division has also been called on Tuesday to discuss the issue, official sources said.

Unofficial reports said at least 20,000 chickens have died so far.

The state Health Department has also formed 12 teams, each comprising a doctor and other health workers, to start rapid culling of the birds, District Magistrate Tapan Shome said.

An isolation ward has been opened in the Rampurhat district hospital to treat any possible bird flu cases.