REPUBLIKA.CO.ID, WASHINGTON -- The state of Washington said Tuesday it has established a third poultry quarantine zone after state officials discovered that a flock of about 100 birds in Okanogan County was infected with the avian influenza virus.

The Washington State Department of Agriculture adopted an emergency rule on Sunday to establish the new quarantine area, which encompasses a six-mile area in Oroville, Wash., state officials said.

State officials are conducting additional tests to identify the specific flue strain that infected the flock. About half of the 100 birds have died, according to agriculture officials.

The quarantine generally restricts the movement of all eggs, poultry or poultry products from leaving that area.