The Associated Press reports: U.S. officials say a drone that crashed inside Iran over the weekend was one of a fleet of stealth aircraft that have spied on Iran for years from a U.S. air base in Afghanistan.

They say the CIA stealth-version of the RQ-170 unmanned craft was also used to survey Osama bin Laden’s compound before the May raid in Pakistan.

According to these officials, the U.S. has built up the air base Shindad, Afghanistan, with an eye to keeping a long-term presence there to launch surveillance missions and even special operations missions into Iran if deemed necessary.

In July, the US Air Force reported: By expanding to nearly three times its original size, Shindand Air Base recently became the second largest airfield throughout Afghanistan.

Colonel Larry Bowers, the 838th Air Expeditionary Advisory Group commander, opened the new expansion area upon completion of construction of approximately eight miles of perimeter fence line.

Having been in the works since fall of 2010, completion of the “Far East Expansion” makes the base second only to Bastion Field in Lashkar Gah in size.

The project is part of a $500 million military construction effort to support Regional Command West and turn Shindand AB into the premier flight-training base in Afghanistan, officials said.

The new expansion is slated to become the new living and working area for more than 3,000 coalition forces and government contractors, officials said. The relocation of these members will make room for a new a 1.3-mile NATO training runway, with construction scheduled to begin in early 2012.