TOKYO, May 5 (Xinhua) -- Two dead swans found respectively on April 24 and Monday in northern Japan's Hokkaido Prefecture have been tested positive of the highly virulent H5N1 strain of the bird flu virus, Kyodo News reported.

    The Japanese Environment Ministry confirmed that the dead swan found on April 24 in eastern Hokkaido's Notsuke Peninsula was infected with the virus, while the Hokkaido prefectural government found the other one dead beside Lake Saroma was also H5N1 positive through a preliminary examination.

    The Hokkaido Prefectural government has carried out in spectionsat five chicken farms within a radius of 30 kilometers around the location of the confirmed case.

    It is the second Japanese prefecture where the H5N1 avian influenza has been detected following that in northeastern Japan's Akita Prefecture in late April.

    On April 29, the H5N1 strain of the bird flu virus was confirmed in several dead and dying swans found a week before in Akita Prefecture.

    No widespread deaths of birds or animals have been reported in both regions.