Second Battle of Yeonpyeong
On June 29, 2002 a North Korean patrol boat crossed the northern limit line and was warned to turn back.
Shortly afterward a second patrol craft crossed the line and it too was warned to retreat back across the line. After traveling three miles south past the limit line, the North Korean vessels attacked the four South Korean patrol boats that had been monitoring them. The vessel that had crossed the line first opened fire with its 85mm gun and scored a direct hit on the wheelhouse of one of the South Korean craft causing several casualties. Two patrol corvettes soon reinforced the South Korean vessels and severely damaged one of the North Korean craft forcing a retreat. The damaged South Korean craft later sunk while under tow. Both sides laid blame on each other and both South Korea and the United Nations demanded an apology from North Korea. North Korea later apologized for the occurrence and promised to take steps to prevent such incidents from occurring in the future
Shortly before 10:00 in the morning on June 28, 2002, two North Korean (NK) Navy patrol boats crossed the Northern Limit Line (NLL) in Korea's West Sea. At approximately 10:25, as Republic of Korea (ROK) Navy ships approached, the North Koreans opened fire, provoking the South Korean Navy to return fire. By approximately 10:50, both NK ships had moved back across the NLL. One of the NK ships was seen to be heavily damaged and on fire. Four South Korean sailors were killed and 18 wounded during the exchange of fire. A disabled ROK ship sank while being towed back to shore.