South Korea's president ordered the military on alert Tuesday for any moves by rival North Korea after the defense minister said last week's explosion and sinking of a South Korean ship may have been caused by a North Korean mine.
The blast ripped the 1,200-ton ship apart last Friday night during a routine patrol mission near Baengnyeong Island, along the tense maritime border west of the Korean peninsula. Fifty-eight crew members, including the captain, were plucked to safety; 46 are missing, with dim prospects for finding any further survivors.
Military officials say the exact cause of the explosion remains unclear, and US and South Korean officials said there was no outward indication of North Korean involvement.
However, Defense Minister Kim Tae-young told lawmakers Monday that a floating mine dispatched from North Korea was one of several scenarios for the disaster.