PATNA, Feb. 22 -- Fresh deaths of crows in Patna and Bhagalpur have raised concerns over a possible spread of the H5N1 avian influenza or bird flu, prompting the Bihar government to intensify containment 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 (RDDL) in Kolkata on February 19 after about 68 crow deaths were reported between February 16 and 18 in different localities of Patna and Bhagalpur," said Sh...