By Kim Hyo-jin



North Korean leader Kim Jong-un secretly visited a military unit near the inter-Korean border in early August, sources said Tuesday.



After Kim's rare visit to the border unit was detected, the South Korean military increased its readiness against the North's possible tactical provocations, the sources said.



Kim reportedly made a secret inspection of the North's border unit, about 1,000 meters away from the South's outpost in Yeoncheon, Gyeonggi Province, early this month.



What Kim did there was not announced, but some raised the possibility that the young leader may have checked on its readiness and gave certain mission orders to the unit.



The border unit is surrounded by mountainous areas and streams, military officials said.



Kim was absent from public appearances for two weeks in early August. He disappeared from the North's media after he attended a July 30 banquet to celebrate the second test-firing of a Hwasong-14 intercontinental ballistic missile.



Later, the leader returned to the media spotlight, Aug. 15, with a visit to the Command of the Strategic Force of the Korean People's Army (KPA).



During the inspection, Kim was briefed by army generals about a planned missile attack on the U.S. Pacific territory of Guam and said he would keep an eye on the U.S.'s behavior, the North's official Korean Central News Agency said.



Seoul and Washington have enhanced their military readiness and surveillance against potential provocations by Pyongyang which has strongly opposed the South Korea-U.S. Ulchi Freedom Guardian joint exercise.



With the onset of the 10-day drill Monday, the Air Force and the U.S. Forces Korea reportedly flew more tactical reconnaissance aircraft and the ROK-U.S. Combined Forces Command put more intelligence agents on alert.



