Defense Minister Kang Shin-chul said Tuesday the mine-clearing operation conducted at the site of a recent blast inside the Demilitarized Zone (DMZ) was a "decisive" response against North Korea, noting it marked the first such mission inside the buffer zone between the two Koreas. Kang made the remarks a day after the South Korean military announced the final result of a joint investigation with the U.N. Command (UNC) into the Sept. 21 mine blast that left three South Korean soldiers injured. The joint probe concluded that antipersonnel mines deliberately planted by North Korean troops south of the Military Demarcation Line (MDL) were the cause of the explosion. "(Such a mine-clearing operation) is unprecedented in history," Kang told reporters at the defense ministry compound. "I believe (the operation) was a decisive response (on our side)," he added. The defense chief brushed aside allegations that the South Korean military's response was too "passive" and "defensive," saying it had taken necessary measures by removing the land mines from the DMZ on Monday. "Our comrades were severely