India, Feb. 22 -- Crow deaths reported from Patna and Bhagalpur districts in Bihar have raised concerns over a possible spread of H5N1 avian influenza, prompting the Bihar government to intensify containment, surveillance and biosecurity measures across five affected districts, officials said on Sunday.

Authorities have collected fresh samples from areas around the Patna high court, the Indira Gandhi Institute of Medical Sciences (IGIMS), AG Colony and Mokama in Patna district, and Sultanganj in Bhagalpur district.

"We have sent fresh samples for testing to the Regional Disease Diagnostic Laboratory in Kolkata on February 19 after about 68 crow deaths were reported between February 16 and 18 in different localities of Patna and Bhagalpu...