The South Korean Navy has concluded a five-day anti-submarine naval drill, which took place close to Baengnyeong, the island nearest to the Yellow Sea border.
According to the Defence Ministry, about 29 ships, 14,000t Dokdo amphibious landing ship, 1,800t submarines, 4,500t Chungmugong Yi Sun-shin Class KDX-II destroyers, 50 fixed-wing aircraft, and 4,500 personnel from army, navy, air force, marine and coastguard platforms participated in the drill.
The underwater firing drills focused on improving the nation's military capabilities to detect North Korean submarines and torpedoes.
The exercise was launched in response to an alleged torpedo attack on a South Korean warship in March 2010.
The Defence Ministry said the anti-submarine drills were its largest-ever excercise conducted near the much-disputed sea border and to showcase its power and to warn North Korea against future provocation.
The North Korean military command warned South Korea of powerful physical retaliation if it proceeded with the excercise, according to the Korea Times.