Inspectors sent to a chicken farm that reported the deaths said initial on-site tests showed the birds did not die of bird flu. Others sent to a second farm that reported a sharp reduction in eggs are trying to determine the cause. Tests on the chickens in the second farm to confirm bird flu have also returned negative.

Both farms are near a duck farm where a bird flu epidemic was reported last week. Asan lies about 80 kilometers south of Seoul.

Officials said that samples of the dead animals and commercial egg-laying chickens have been sent to National Veterinary Research and Quarantine Service for a more detailed analysis. Results of these tests are expected Wednesday.

The large-scale death of the animals and the reduction in egg production are tell-tale signs of a virulent strain of avian influenza that has hit the country in recent months.

The Ministry of Agriculture and Forestry reported four separate cases of the disease since November.

The government has culled more than a million birds to prevent the spread of the flu.

ThePoultrySite News desk