The Pentagon confirmed on Thursday that two Iranian fighter planes fired on, but did not hit, an unarmed US drone late last week.

The incident was first reported by CNN, and Pentagon spokesman George Little confirmed the incident on Thursday.

Reuters adds:

President Barack Obama and Defense Secretary Leon Panetta were both advised early on about the incident, which occurred at about 4:50 a.m. ET on November 1. Iran was later warned that the United States would continue to conduct such surveillance flights in the region and that the military would protect its assets.

Little said the drone aircraft was conducting "routine surveillance" and was about 16 miles off the Iranian coast when an Iranian SU-25 warplane intercepted it and opened fire. He said this was first time a US drone had been shot at in international airspace over the Gulf.

That last claim may or may not be true, but this is not the first time that Iran has confronted US spy drones near or within its airspace.

In late 2011, Iran's military shot down a US reconnaissance drone aircraft in eastern Iran and later sent a complaint to the United Nations for the incursion.

"Provocative and secret actions by the American government against the Islamic republic would not be tolerated" Iranian officials said in the complaint.

The Iranians made specific warnings against any "repetition of such actions."

At the time, the US government claimed the drone crashed and was not shot down. They did, however, request the pilotless drone be returned.