Above: IRNA photo associated with Iranian claim
Iran has claimed to have downed a U.S. military RQ-170 Sentinel stealth drone that violated Iran's eastern border with Afghanistan.
NATO has stated this drone may be the same one that it lost over western Afghanistan last week:
"The UAV to which the Iranians are referring may be a US unarmed reconnaissance aircraft that had been flying a mission over western Afghanistan late last week. The operators of the UAV lost control of the aircraft and had been working to determine its status." -- ISAF statement
The RQ-170 Sentinel stealth drone is the same kind that was used to find and monitor Osama Bin Laden when his compound at Abbotabad Pakistan was discovered earlier this year.
Iranian media reported last July that it shot down a US drone near the Fordu nuclear site in Qom.