South Korean soldiers look through binoculars at a military checkpoint in Paju, South Korea, near the border village of Panmunjom, on Sunday, May 19, 2013. The South Korean military on Sunday beefed up its monitoring of North Korea and is maintaining a high-level of readiness to guard against provocations by the North. (AP Photo/Ahn Young-joon)

Photo by: Ahn Young-joon

South Korean soldiers look through binoculars at a military checkpoint in Paju, South Korea, near the border village of Panmunjom, on Sunday, May 19, 2013. The South Korean military on Sunday beefed up its monitoring of North Korea and is maintaining a high-level of readiness to guard against provocations by the North. (AP Photo/Ahn Young-joon)