
A South Korean naval ship participates during a military exercise in the West Sea of South Korea, 05 August 2010. South Korean troops fired artillery and dropped sonar buoys into the Yellow Sea as naval drills kicked off near the spot where a warship sank four months ago. EPA/SONG KYUNG-SEOK - POOL

A South Korean Navy's Lynx helicopter carries a sonar (Sound Navigation and Ranging) to locate submarines during a military exercise in the West Sea of South Korea, 05 August 2010. South Korean troops fired artillery and dropped sonar buoys into the Yellow Sea as naval drills kicked off near the spot where a warship sank four months ago. EPA/LEE JIN-MAN - POOL POOL PHOTO

South Korean naval 14,000 ton-class large-deck landing ship Dokdo is seen during a military exercise in the West Sea of South Korea, 05 August 2010. South Korean troops fired artillery and dropped sonar buoys into the Yellow Sea as naval drills kicked off near the spot where a warship sank four months ago. EPA/SONG KYUNG-SEOK - POOL

A South Korean naval ship participates during a military exercise in the West Sea of South Korea, 05 August 2010. South Korean troops fired artillery and dropped sonar buoys into the Yellow Sea as naval drills kicked off near the spot where a warship sank four months ago. EPA/SONG KYUNG-SEOK - POOL

A South Korean naval ship participates during a military exercise in the West Sea of South Korea, 05 August 2010. South Korean troops fired artillery and dropped sonar buoys into the Yellow Sea as naval drills kicked off near the spot where a warship sank four months ago. EPA/SONG KYUNG-SEOK - POOL

South Korean navy's 14,000 ton-class large-deck landing ship Dokdo is seen during a military exercise in the West Sea of South Korea, 05 August 2010. South Korean troops fired artillery and dropped sonar buoys into the Yellow Sea as naval drills kicked off near the spot where a warship sank four months ago. EPA/LEE JIN-MAN - POOL

A South Korean Navy's Lynx helicopter leaves from the destroyer Choi Young during a military exercise in the West Sea of South Korea, 05 August 2010. South Korean troops fired artillery and dropped sonar buoys into the Yellow Sea as naval drills kicked off near the spot where a warship sank four months ago. EPA/LEE JIN-MAN - POOL

A South Korean naval ship participates during a military exercise in the West Sea of South Korea, 05 August 2010. South Korean troops fired artillery and dropped sonar buoys into the Yellow Sea as naval drills kicked off near the spot where a warship sank four months ago. EPA/SONG KYUNG-SEOK - POOL