The Associated Press is reporting that a warning was issued earlier this year that North Korea was planning a suicide submarine attack on a South Korean naval vessel in retaliation for an earlier naval engagement which the north lost.
On Thursday, the mass-circulation Chosun Ilbo newspaper reported the Korea Defense Intelligence Command alerted the navy weeks ahead of the ship sinking that North Korea was preparing underwater suicide teams in mini-submarines to attack the South.
These "human torpedo" squads were said to involve small submarines navigated so close to the target that their torpedoes or explosives blow up both target and the attackers, or are timed to explode while the attackers escape from the vehicle, the report said.
The attack preparations were aimed at retaliating against the South over its defeat in a naval skirmish in November, the paper said. The site of the sinking is near where the rival Koreas fought three times since 1999, most recently a November clash that left one North Korean soldier dead and three others wounded.