A naval mine dispatched from North Korea, possibly during the Korean War, may have struck a South Korean warship that exploded and sank near the Koreas' disputed sea border, the defense minister told lawmakers March 29, laying out several scenarios for the maritime disaster.

Defense Minister Kim Tae-young said there was no sign of a direct attack from rival North Korea, but military authorities have not ruled out North Korean involvement in the sinking of the 1,200-ton Cheonan on March 26.

An explosion ripped the 1,200-ton ship apart during a routine patrol mission near Baengnyeong Island west of the peninsula. Fifty-eight crew members, including the captain, were plucked to safety; 46 remain missing.

Kim ruled out a torpedo attack from North Korea, which would have been spotted by radar.