South Korea on Tuesday confirmed a second outbreak of the H5N1 strain of bird flu at a poultry farm, after confirming over the weekend it had its first outbreak in three years of the strain that can kill people.

The agriculture ministry said about 600 chickens died in the latest outbreak at a farm 3 km (2 miles) from where the first case had been confirmed in poultry in North Cholla province in the country´s southwest.

There were no reports to suggest residents or quarantine officials had been infected in or around both infected farms, an agriculture official said by telephone.

"The test results have shown that we had a second case of highly pathogenic H5N1 bird flu," the ministry said in a statement.

Quarantine authorities would cull all poultry within a 500 meter (1,640 ft) radius of the latest infected farm.

The farms lie on a path for migratory birds that are heading south from Russia, Mongolia and Kazakhstan and sparked concern that other parts of South Korea might have also been hit.

South Korea had planned to cull 236,000 poultry by Thursday within a 500-meter radius of the first infected farm in North Cholla province, about 170 km (105 miles) south from Seoul. It had by Monday culled 75,500 poultry and disposed of 6.6 million eggs in the same area.

Bird flu killed about 6,000 chickens in the first outbreak.

Between December 2003 and March 2004, about 400,000 poultry at South Korean farms were infected by bird flu.

During that outbreak, the country destroyed 5.3 million birds and spent about 1.5 trillion won ($1.6 billion) to prevent the disease spreading, officials said.

Subsequent testing in the United States indicated at least nine South Korean workers involved in the culling had been infected with the H5N1 virus, but none developed major illnesses.

The vast majority of human bird flu cases involving the H5N1 virus have been linked to direct or indirect contact with infected fowl.  

Indonesia said on Tuesday a 35-year-old woman died of the disease, bringing that country´s death toll to 57, the highest for any nation.

Bird flu remains essentially an animal disease, but it has infected nearly 260 people worldwide since late 2003, killing more than 150, according to the World Health Organization.

Since 2003, outbreaks have been confirmed in about 50 countries and territories.