A Lynx helicopter of the South Korean navy leaves from the destroyer Choi Young during military drills in the Yellow Sea of South Korea's west coast on Thursday, Aug. 5, 2010. South Korean troops fired artillery and dropped sonar buoys into the sea as naval drills kicked off Thursday near the spot where a warship sank four months ago. (AP Photo/Lee Jin-man, Pool)

Photo by: Lee JIn-man

A Lynx helicopter of the South Korean navy leaves from the destroyer Choi Young during military drills in the Yellow Sea of South Korea's west coast on Thursday, Aug. 5, 2010. South Korean troops fired artillery and dropped sonar buoys into the sea as naval drills kicked off Thursday near the spot where a warship sank four months ago. (AP Photo/Lee Jin-man, Pool)