RIYADH, Saudi Arabia - Saudi Arabia said Tuesday it had killed some 158,000 chickens after the deadly H5N1 bird flu strain was found at an infected farm.

The birds were killed in Kharaj province, south of the capital, Riyadh, according to a statement by the Agriculture Ministry. About 475 workers were tested, but no human infections were found.

The ministry also said more than 4.5 million fowl have been killed in provinces around the capital, but it did not specify when the killing took place.

Bird flu resurfaced in November in Kharaj province, in another blow to Saudi Arabia"e;s $10 billion poultry industry.

To stem the flu"e;s spread, some countries temporarily banned imports of birds, poultry and poultry products from Saudi Arabia earlier this month.

H5N1 so far has infected more than 340 people and killed at least 216 since 2003, mostly in Asia, according to the World Health Organization. Most were infected through close contact with sick poultry. The virus does not easily spread among people.