VANCOUVER - A fifth poultry farm has been placed under quarantine in British Columbia's Fraser Valley, where an estimated 140,000 birds are expected to be euthanized to contain the avian flu.

Canada's chief veterinary officer, Dr. Harpreet Kochhar, says the virus has now been confirmed at a second turkey farm in Abbotsford, after a producer volunteered to have the animals tested.

On Friday, officials with the Canada Food Inspection Agency began destroying birds at a broiler-breeder chicken farm in Chilliwack, where the H5N2 strain of flu was first detected.

B.C.'s chief veterinary officer Dr. Jane Pritchard says the latest farm to be quarantined had no links with the other facilities.

Seven countries have now placed restrictions on importing poultry or poultry products from B.C. or Canada.

The highly contagious virus has spread despite a three-kilometre containment zone around the infected farms, and Kocchar says that may be due to migratory birds.