ISLAMABAD The NATO mission in Afghanistan has been found guilty of gross violation of Standing Operating Procedures (SOPs), as its two helicopters attacked a Pakistani military post in the Upper Kurram Agency last week and killed three soldiers, besides injuring three others. This was found during the joint probe into the incident conducted by military and civil officials from the NATO, Pakistan and the US. The team has drawn the conclusion that NATO helicopters did not follow at all the rules of engagement. Well-placed sources privy to these developments informed TheNation on Tuesday that International Security Assistance Force (ISAF) in Afghanistan would shortly issue an official statement over the findings. Sources further said that NATO officials found guilty would also face judicial inquiry and would be punished according to NATO rules. Sources said that ISAF Commander General David Petraeus would also visit Pakistan shortly to formally express his regrets and apology to Pakistans political and military leadership.