SEOUL (Reuters) - South Korea on Monday confirmed a newoutbreak of bird flu at a duck farm in the southwest and saidit was investigating two other possible cases days afterreporting an outbreak at a nearby chicken farm.

Quarantine workers had started culling 6,500 ducks at theJeongeup farm, where 6,000 poultry have died since last week,and had destroyed thousands of birds which had already beensent elsewhere, the Farm Ministry said.

They were also investigating two nearby duck farms wherehundreds of birds had died over the weekend.

The area is only 27 km (17 miles) from the chicken farm inGimje, about 215 km south of Seoul, which reported thecountry's first outbreak of H5N1 in 13 months.

The farm ministry banned distribution of 3.6 million birdswithin a 10 km radius of the Gimje site and the destruction ofeggs distributed from the area.

South Korea had seven outbreaks of the deadly H5N1 strainof bird flu between November 2006 and March 2007 and has spent58 billion won ($59 million) on quarantine measures.

Bird flu has killed 238 people globally since 2003,according to the World Health Organisation. The big concern isthat it could mutate into a disease that easily passes from oneperson to another, triggering a deadly global pandemic.

(Reporting by Miyoung Kim; Editing by Nick Macfie)