South Korean navy commandos found the bodies of nine North Koreans in a captured submarine Friday, all shot to death in an apparent suicide pact.
South Korea said the sub, spotted after becoming entangled in a South Korean fisherman's net earlier this week, was on a spy mission and the Defense Ministry demanded the North apologize."North Korea must acknowledge that the incident was a serious act of provocation, punish those involved and take action to prevent the recurrence of similar incidents," the ministry said.
The ministry rejected an earlier North Korean claim that the submarine went missing on a routine training mission after experiencing mechanical problems.
It also said it was asking the American-led U.N. command to lodge a formal protest.
The Koreas were divided into the communist North and the capitalist South in 1945. Technically, they remain at war because an armistice, not a peace treaty, ended the 1950-53 Korean War.
President Kim Dae-jung denounced the sub's intrusion but said the incident would not sway his policy for expanded exchanges and cooperation to improve relations with the reclusive North.