North Korea's foreign ministry warned on Oct. 6 that its border guards would take "immediate and powerful counteraction" if South Korea intrudes "even a millimeter" into its territory, a day after Seoul's military blamed North Korean mines for a Sept. 21 blast that critically injured two South Korean soldiers in the Demilitarized Zone (the heavily fortified buffer strip dividing the two Koreas) and carried out a mine-clearing operation at the site with the U.N. Command. Pyongyang denied planting the mines, called Seoul's claims a fabricated "farce," and rejected talks on the border line, while South Korea's unification minister has proposed discussions because most of the 1953 ceasefire-line markers have deteriorated. The exchange raises tensions along a poorly marked frontier where Seoul has vowed a "decisive" response and the two sides have no agreed channel to resolve disputes.