ISLAMABAD, March 21 (Xinhua) -- Pakistan's first two cases of the deadly H5N1 strain of bird flu in chickens in the country's North West Frontier Province have been confirmed by lab tests, the government announced Tuesday.

    The samples containing H5N1 bird flu virus were taken from chickens at two farms late last month, private Geo News television channel reported on Tuesday.

    Tests conducted in Britain confirmed the sub-type to be H5N1.

    "They (the British lab) have also endorsed the finding of our laboratory that infection was avian influenza H5N1," an Agriculture Ministry statement said.

    The flocks have since been culled, and officials say they have not found any other incidents of bird flu.

    No human cases were detected, said Mohammad Afzal, spokesman for the Food, Agriculture and Livestock Ministry.

    Pakistan early this month culled 25,000 chickens at the farms in the towns of Charsadda and Abbottabad after confirming the presence of the broad H5-type virus, and had since been awaiting the test results.

    The H5N1 strain has killed about 100 people in seven countries since 2003. Scientists fear a global pandemic if the virus mutates and becomes easily transmissible between humans. Enditem