A surveillance drone flying over western Afghanistan had gone out of control late last week and may be the one Iran said it had shot down over its own airspace, the International Security Assistance Force (ISAF) has said.

"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," an ISAF statement said on Sunday.

The statement was issued in Kabul and released to reporters covering an international conference on Afghanistan in the German city Bonn.

A US official told the Reuters news agency that there is "absolutely no indication" up to this point that the drone that crashed in Iran was shot down.

Iranian media reported on Sunday that its forces had brought down an unmanned US spy plane.

"Iran's military has downed an intruding RQ-170 American drone in eastern Iran," Iran's Arabic-language Al Alam state television network quoted an unnamed source as saying on Sunday.
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