OTTAWA, Oct. 31 (Xinhuanet) -- Several birds in Canada have been discovered to be carrying unidentified H5 flu viruses, but it is not known if they have H5N1 virus, the dangerous subtype of the avian flu, health officials confirmed Monday.

    The infected wild birds were discovered in Quebec and Manitoba and were among thousands sampled in Canada, officials from the Canadian Food Inspection Agency said.

    "Preliminary testing has identified H5 influenza in 28 samples from Quebec, and five from Manitoba," Jim Clark of the Canadian Food Inspection Agency told a news conference.

    However, it will not be known until mid-week whether the birds carry the dangerous H5N1 subtype of the avian flu.

    Even if the Canadian birds are carrying the H5N1 virus, it doesnot mean they are necessarily related to the viruses behind the poultry outbreaks in southeast Asia, officials stressed.

    "It is important to clarify that the avian influenza virus is not new to wild birds. Experts worldwide know that this virus ... has circulated among wild birds around the world for hundreds, or perhaps even for thousands of years," Clark said.

    So far, the outbreaks in Asia have infected 121 people and caused more than 60 deaths in Thailand, Vietnam, Indonesia and Cambodia.

    Earlier this month, Australia imposed a ban on live bird imports from Canada after three imported Canadian racing pigeons tested positive for bird flu antibodies. The ban was later lifted after officials in Ottawa provided compelling evidence proving Canada free of H5N1. Enditem