LONDON, April 6 (Xinhua) -- A swan found dead in Scotland has tested positive for the deadly H5N1 strain of bird flu, the Scottish Executive confirmed on Thursday in a statement.

Some swans are seen in a park in Scotland, April 6, 2006. A swan found dead in Scotland has tested positive for the deadly H5N1 strain of bird flu, the Scottish Executive confirmed on Thursday in a statement.

    The Scottish Executive has extended surveillance zones in Scotland to include 175 properties with 3.1 million birds, as wellas free-range poultry.

    The dead swan was found in Cellardyke, Fife, eight days ago. Other birds are being tested.

    Scottish Chief veterinary officer Charles Milne told an Edinburgh press conference earlier Thursday that a "wild bird riskarea" would be set up in a 2,500-square kilometer area."

    He said, "We are proposing to issue a veterinary directive to owners of poultry to house their birds where possible."

    He said that if that was not possible, they would be expected to put in place measures to separate their birds from wild birds.

    Gatherings of birds in that area would be banned, Milne said, and there would be enhanced surveillance of wild birds.

    Officials stressed that there was no reason for public health concern.

    The H5N1 virus does not at present pose a large-scale threat tohumans, as it cannot pass easily from one person to another.

    However, experts fear the virus could mutate to gain this ability, and in its new form trigger a flu pandemic, potentially putting millions of human lives at risk.

    According to the National Farmers Union Scotland, the Scottish poultry industry produces 127,000 tones of meat and 740 million eggs. However, no poultry farms are thought to be in the immediatearea of flu case. Enditem