By Jun Ji-hye



Tension is building along the inter-Korean border as the South is beefing up military readiness in response to last week's mine explosion in the Demilitarized Zone (DMZ) blamed on the North.



The Ministry of National Defense said Tuesday troops along the border are on high alert to ensure an immediate response to any additional provocations by North Korean troops.



The South Korean military resumed loudspeaker propaganda broadcasting Monday, after having not done so for 11 years, as the first step in retaliation against the North for the land mines that maimed two South Korean soldiers.



When the South announced a plan to resume the propaganda broadcasting in 2010 as part of a psychological warfare program in the wake of the North's deadly torpedoing of the South Korean Navy frigate Cheonan, the North threatened to shoot at the loudspeakers. The broadcasting did not resume at that time.



Defense ministry spokesman Kim Min-seok told reporters that South Korean forces will take immediate action, including firing at anyone in the North who shoots at the loudspeakers.



"Our forces are closely monitoring movements of North Korean soldiers and have enhanced their readiness posture in preparation for any additional provocations," he said. "North Korea has yet to show any response to the broadcasting."



Officials said the military has reinforced the deployment of unmanned surveillance vehicles, anti-tank missiles and AN/TPQ-36 artillery location radar in areas where the loudspeakers are placed.



Earlier in the day, Defense Minister Han Min-koo told lawmakers that the military will execute operations to "take control" of the DMZ, a 4-kilometer wide buffer zone separating the two Koreas, the legacy of the ceasefire that ended the Korean War (1950-53).



He made the comments during a meeting with ruling party lawmakers attended Rep. Chung Doo-un, chairman of the National Assembly Defense Committee.



"The ministry is reviewing follow-up measures after resuming the loudspeaker propaganda broadcasting," Han said.



Kim explained that Han's comments mean enhancing the military's search and ambush operations to prevent North Korean soldiers from crossing the Military Demarcation Line (MDL).



A ministry official noted on the condition of anonymity that the existing concepts of the operations in the border areas have been designed to block the enemy's crossing of the MDL, but this would be changed to "destroy" the enemy in the DMZ.



Toward that end, the military is seeking to simplify its operations applied to North Korean soldiers who cross the MDL by reducing the three steps ― warning messages, warning shots and aimed shots ― to one step ― aimed shots, the official said.



He added that the military is planning to carry out search missions at irregular times and places to confuse the North, based on the belief that the reclusive state has already learned the times and places of South searches. It is believed that the North has been able to plant land mines in the DMZ after successfully avoiding South patrols.



For its part, the presidential office called on the isolated state to apologize for its provocation.



"We demand the punishment of those in charge," said Cheong Wa Dae spokesman Min Kyung-wook.



Three North Korean-made wooden box antipersonnel landmines exploded on the morning of Aug. 4 inside the DMZ near Paju, Gyeonggi Province, when eight South Korean 1st Infantry Division soldiers were on routine patrol.



A staff sergeant indentified only by the surname of Ha lost both his legs from below the knees, while another staff sergeant surnamed Kim had his right foot amputated from the ankle.



Follow Jun Ji-hye on Twitter @TheKopJihye



