South Korea urged North Korea to take "responsible measures" Thursday at the United Nations, accusing Pyongyang of violating the Armistice Agreement by deliberately planting a land mine that injured three South Korean soldiers near the inter-Korean border last month. During a committee meeting of the 81st session of the U.N. General Assembly in New York, South Korean Ambassador to the U.N. Cha Ji-hoon said a joint investigation by the South Korean military and the United Nations Command (UNC) confirmed that a Sept. 21 explosion was caused by a land mine deliberately planted by North Korean forces south of the Military Demarcation Line (MDL) separating the two Koreas. "A joint on-site investigation by ROK military and the UNC supported by forensic analysis confirmed that the explosion was caused by a landmine deliberately planted by DPRK forces south of the military demarcation line," Cha said, referring to the two Koreas by their official names, the Republic of Korea and the Democratic People's Republic of Korea, respectively. Cha said the incident constituted a clear violation of the A