Seoul — — Evidence overwhelmingly proves North Korea fired a torpedo that sank a South Korean warship in March, killing 46 sailors, investigators said Thursday.
South Korean President Lee Myung-bak vowed "stern action" for the provocation and called an emergency security meeting for Friday.
The long-awaited investigation results from a multinational team said a torpedo caused a massive underwater explosion that tore the Cheonan apart on March 26.
Fifty-eight sailors were rescued from the frigid Yellow Sea waters near the two nations' maritime border, but 46 perished, South Korea's worst military disaster since the 1950-53 Korean War.
Recovered fragments from the sea floor indicate the torpedo came from communist North Korea, investigators said.
North Korea responded to the findings by saying it would take strong measures, including war, if the South imposes sanctions after accusing it of sinking a navy ship, Yonhap news service said.