Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. US Apologizes for Raid that Killed Pakistani Soldiers VOA News 06 October 2010 Photo: AP General David Petraeus (file) The United States apologized to Pakistan Wednesday for a NATO helicopter raid that killed two Pakistani soldiers at an outpost near the Afghan border, saying the soldiers were mistaken for insurgents. General David Petraeus, who leads U.S. and NATO forces in Afghanistan, said coalition forces "deeply regret" the loss of life. He vowed they would work more closely with the Pakistani military to ensure such an incident does not happen again. The U.S. ambassador to Pakistan also apologized for the soldiers' deaths, calling the incident a "terrible accident." A joint Pakistani-NATO investigation has found that the attack could have been avoided with better coordination between coalition forces and the Pakistani military. The raid happened last Thursday, when NATO helicopters crossed Pakistan's border while in pursuit of insurgents. The investigation found that two coalition helicopters fired on what turned out to be a Pakistani border outpost, after shots were fired from the building. The report says investigators believe that a Pakistani border guard fired to warn the helicopters. After the NATO raid, Pakistan shut down the Torkhum border crossing in the Khyber tribal region, choking a key NATO supply route into Afghanistan. There have been a string of attacks on NATO supply vehicles since then. On Wednesday, gunmen set fire to 25 oil tankers, killing one driver. Authorities say the attackers struck at a depot outside the western city of Quetta. The Pakistani Taliban claimed responsibility for the attack. Later Wednesday, militants opened fire on another convoy of NATO oil tankers in Pakistan.  U.S. officials say they are working with Pakistani authorities to re-open the Torkhum border crossing as soon as possible. Elsewhere Wednesday, military officials say a U.S. drone strike killed three militants in northwestern Pakistan. Some information for this report was provided by AP, AFP and Reuters. .