Four military officers, who were charged with negligence of duty in the terrorist attack in Turkey's southeastern Diyarbakır province which killed 13 Turkish soldiers in 2011, have been acquitted on Wednesday.13 Turkish soldiers and seven members of the outlawed PKK, were killed in southeastern Turkey on July 14, 2011 in an ambush on Turkish troops in Diyarbakır's Silvan town.Following the attack, some senior commanders in Silvan were relieved of duty and two separate investigations were launched by the General Staff and Interior Ministry. On Wednesday's trial, the judges announced that the four officers were not guilty and negligence and misconduct did not play a role in the attack.