A North Korean soldier looks out of the window of a guard tower, on the banks of Yalu River, about 62 miles from the North Korean town of Sinuiju, opposite the Chinese border city of Dandong, on April 16.
North Korea issued new threats against South Korea on Tuesday, vowing "sledge-hammer blows" of retaliation if South Korea did not apologize for anti-North Korean protests the previous day when the North was celebrating the birth of its founding leader.-NBC News.com
