( CNN ) -- Four former Blackwater private security contractors faced new federal charges on Thursday , the latest chapter in a controversial political and diplomatic case over a deadly 2007 Iraqi War incident . The men were re-indicted by a federal grand jury in Washington on various manslaughter charges related to a shooting that left 17 unarmed Iraqi civilians dead and at least 18 others wounded at Nisur Square in Baghdad . The indictment alleges the men `` unlawfully and intentionally , upon a sudden quarrel and heat of passion , did commit voluntary manslaughter . '' The defendants have denied all charges and said they acted in self-defense when fired upon initially by militants . A federal judge in 2008 dismissed the original case , finding the Justice Department withheld key evidence , and violated the guards ' rights . But a federal appeals court later reversed that decision , leading the government to seek a fresh indictment . The incident prompted international outrage at the time , and the criminal prosecution in the United States has dragged on for years . 2011 : Blackwater founder enters video game business . The killings led Iraq 's government to slap limits on security contractors hired by various firms , including Virginia-based Blackwater -- now under new management and known as Academi . `` The vast majority of the U.S. contractors who served in Iraq did so with honor and integrity , but , as alleged today , these defendants abused their power through a relentless attack on unarmed civilians that recklessly exceeded any possible justification , '' said U.S. Attorney Ronald C. Machen Jr. `` This prosecution demonstrates our commitment to upholding the rule of law even in times of war and to bringing justice to the memories of those innocent men , women , and children who were gunned down in Baghdad more than six years ago , '' he said . There was no immediate reaction from attorneys for the men . There was no indication when a new criminal trial would begin . The case is U.S. v. Slough , et al ( cr-08-360 ) .
Private security contractors reindicted by grand jury on manslaughter charges . Incident related to shooting in 2007 that left 17 unarmed Iraqi civilians dead . Iraq had denied all charges previously , saying they acted in self defense . Incident prompted international attention as U.S. prosecution has dragged on for years .