(AP) -- South Korea's government confirmed a fourth outbreak of the H5N1 bird flu virus in the country's southwest Sunday, as the tally of birds slaughtered to control the spread of the disease rose to 1.3 million.
Government tests confirmed the latest H5N1 outbreak at a farm in Yeoungam, about 236 miles southwest of Seoul, Agriculture Ministry official Kim Chang-sup said.
Earlier this month, South Korea reported its first case of H5N1 in more than a year. Since then, three more H5N1 outbreaks have been confirmed, Kim said. Six further outbreaks were being tested for the deadly strain, he said.
Quarantine workers have slaughtered 470,000 chickens and ducks at 20 farms within a 1.8 mile radius of the site of the latest outbreak, according to Ryu Chul-hyuk, an official of the South Jeolla provincial government.
More than 1.3 million ducks and chickens have been slaughtered this month in H5N1 affected areas in the southwest, according to the ministry.
Seven outbreaks of the deadly virus hit poultry farms across South Korea between November 2006 and March 2007, resulting in the slaughter of about 2.8 million birds.
At least 239 people worldwide have died from bird flu since 2003, according to the World Health Organization. So far, most human cases have been linked to contact with infected poultry.
The disease is relatively difficult for humans to catch, but health authorities fear it could mutate into a form that is easily spread among humans, which could cause a flu pandemic.