It was estimated that around 220,000 civilians killed by US/ARVN operations were miscounted as " enemy KIA " as when free-fire zones were declared it was erroneously assumed all individuals were enemy combatants For official US military operations reports , there are no distinctions between enemy KIA and civilian KIA since it was assumed by US forces that an area declared a free-fire zone that all individuals killed regardless of whether they were combatants or civilians were considered enemy KIA . Since body counts was a direct measure of operational success this often caused US battle reports to list civilians killed as enemy KIA . The inclusion of civilians killed led to the enormous discrepancy between weapons seized and " enemy KIA " during Operation Speedy Express , with nearly 10,000 enemy KIA with just 748 weapons found . Most of the those counted as " enemy killed " were unarmed civilians . The My Lai Massacre and Son Thang massacre both reported women and children killed as " enemy combatants "
Son Thang massacre
Son Thang massacre
Vietnam War body count controversy