The Agriculture Ministry said several pigs were found stricken with foot-and-mouth at the farms in Ansung and Yongin, both 60 miles south of the capital and about a mile from the two farms where health authorities slaughtered nearly 12,000 pigs a week ago.

"There is fear that the foot-and-mouth disease may be spreading," said Park Sun-sook, chief spokeswoman of President Kim Dae-jung. "Farmers and the government must work together to block the spread of the disease."