South Korea's military will install underwater sensors near its tense sea border with North Korea to guard against an attack by the North's submarines. The Maeil business newspaper said today that the military plans to place the sensors near frontier islands in the Yellow Sea, the scene of bloody naval battles in 1999, 2002 and November 2009. A South Korean corvette sank near the disputed border last March after what the South said was a torpedo attack from a North Korean submarine, a charge denied by Pyongyang. The sinking cost 46 lives. In November last year the North shelled Yeonpyeong island, killing four people including civilians.””