Did American forces massacre Iraqi civilians in cold blood? That is the explosive question being asked after a video surfaced. Filmed by a journalism student, it purportedly shows the aftermath of a US raid on two private homes.Locals say that after a bomb killed a Marine nearby, soldiers cordoned off the area, burst into the houses and shot dead 15 people. According to a relative of a survivor, those killed included girls aged three, five, and ten. The video has apparently not been independently authenticated or dated. The incident took place in the western town of Haditha last year. The US military described it as an ambush on a patrol that left a soldier, eight insurgents and 15 civilians dead – in the bombing and subsequent firefight. The army admits killing non-combatants but says they were victims of “collateral damage” not murder. Several Marines are under investigation for possible war crimes.