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The Obama administration is expanding its drone program far beyond Pakistan, building secret bases in the Horn of Africa and Arabian Peninsula in a move to target dangerous al Qaeda affiliates.

A senior U.S. military official with knowledge of the program told Fox News that the expansion has been underway for over a year. It started with a base in Seychelles, an archipelago northeast of Madagascar. Officials have been eyeing Ethiopia, described as the "basing location of choice," but so far have only been able to fly surveillance drones from Ethiopian bases. Armed drones, though, are being flown out of the small African country of Djibouti.

The locations were first reported by The Washington Post. The drone program has ramped up significantly in recent years under the Obama administration, being used primarily to take out top terror leaders in the vast tribal areas of Pakistan.

Drone attacks have also been reported in Libya, Somalia and Yemen, as well as the two more formal war zones of Afghanistan and Iraq. U.S. officials had confirmed to Fox News earlier this year that the CIA would mount an operation in Yemen with drone strikes, virtually identical to the mission in Pakistan.

The expanding operation would likely be aimed at terror groups in both Yemen and Somalia. It reflects increasing concern among officials that as U.S. and Pakistani forces put pressure on the al Qaeda core in Pakistan, affiliate groups -- particularly Yemen-based al Qaeda in the Arabian Peninsula -- are posing a bigger threat.

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Director of National Intelligence James Clapper and newly appointed CIA Director David Petraeus made this point in a recent congressional hearing.

As part of the expanded program, the senior U.S. military official said the United States got permission to fly armed drones from Djibouti, and confirmed the construction of a new airstrip in the Arabian Peninsula.

The official said that was the "only new expansion to this plan.

"The rest has been working for over a year when we long ago realized danger from AQAP," the official said, describing the process as a "long-term deliberate effort where we used what we could (until) we got the locations we wanted."

The Washington Post based some of its reporting on cables released by WikiLeaks.

In the case of the Seychelles base, officials previously claimed that drones were being used to track pirates. But, according to the Post, the cables showed they've conducted missions over Somalia hundreds of miles away.

Fox News' Jennifer Griffin and Catherine Herridge contributed to this report.