An unmanned aerial drone allegedly shot down by Iranian forces might have been a rogue vehicle belonging to the U.S. military, ISAF said. Iranian military officials told the semiofficial Fars News Agency, on condition of anonymity, that Iranian forces shot down a RQ-170 drone near the eastern border with Afghanistan. \"An advanced RQ-170 unmanned American spy plane was shot down by Iran\'s armed forces,\" an official said. \"It suffered minor damage and is now in possession of Iran\'s armed forces.\" The NATO-led International Security Assistance Force in Afghanistan said it believed the Iranians had downed an American surveillance drone. \"The UAV to which the Iranians are referring may be a U.S. unarmed reconnaissance aircraft that had been flying a mission over western Afghanistan late last week,\" ISAF said in a statement. \"The operators of the UAV lost control of the aircraft and had been working to determine its status.\" Tehran maintained the drone was shot down with the help of what Fars described as an electronic warfare unit in the Iranian military. The Iranian government also claimed this wasn\'t the first time it shot down a U.S. drone over its airspace. Officials in Tehran said future responses to U.S. surveillance activity wouldn\'t \"be limited to Iran\'s borders anymore.\" A 2009 report from Aviation Week revealed the Lockheed Martin-designed craft could be used to peer across Iranian, Chinese, Indian or Pakistani borders. U.S. Air Force officials told the magazine at the time that that the military was developing a reconnaissance system to support forward deployed combat forces in Afghanistan.