Culling operations are continuing in bird flu affected Pubong village under Takdah block of Darjeeling Sadar sub-division and Matigaraha under Siliguri sub-division.
Talking to reporters, the District Magistrate of Darjeeling, Surendra Gupta, said samples of dead chicken are being sent to Bhopal for tests.
"Culling operation will be completed in the next six days," he added.
The main epicenter of the flu has been fixed at Binay Krishna Pally off Siliguri in the District of Darjeeling.
The latest outbreak of the virus in poultry is the fourth in West Bengal since 2007.
Bird flu first broke out in India in 2006 and millions of chicken and ducks had been culled to contain the virus.
Although it has resurfaced from time to time, there have been no reports of any human infections in India.
Earlier, hundreds of thousands of birds had been culled in Assam and neighboring Meghalaya after bird flu was detected in November last year.
Experts have warned that the H5N1 virus might mutate or combine with the highly contagious seasonal influenza virus and spark a pandemic that could kill millions of people across the world.