AP IMPACT: Thousands Killed By U.S.'s Korean Ally

Grave by mass grave, South Korea is unearthing the skeletons and buried truths of a cold-blooded slaughter from early in the Korean War, when this nation's U.S.-backed regime killed untold thousands of leftists and hapless peasants in a summer of terror in 1950.

With U.S. military officers sometimes present, and as North Korean invaders pushed down the peninsula, the southern army and police emptied South Korean prisons, lined up detainees and shot them in the head, dumping the bodies into hastily dug trenches. Others were thrown into abandoned mines or into the sea. Women and children were among those killed. Many victims never faced charges or trial.

The mass executions — intended to keep possible southern leftists from reinforcing the northerners — were carried out over mere weeks and were largely hidden from history for a half-century. They were "the most tragic and brutal chapter of the Korean War," said historian Kim Dong-choon, a member of a 2-year-old government commission investigating the killings.

Through the postwar decades of South Korean right-wing dictatorships, victims' fearful families kept silent about that blood-soaked summer. American military reports of the South Korean slaughter were stamped "secret" and filed away in Washington. Communist accounts were dismissed as lies.

Only since the 1990s, and South Korea's democratization, has the truth begun to seep out.

Hundreds of sets of remains have been uncovered so far, but researchers say they are only a tiny fraction of the deaths. The commission estimates at least 100,000 people were executed, in a South Korean population of 20 million.