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) said on Sunday.

The UAV to which the Iranians are referring may be a U.S. 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.

The statement about the unmanned aerial vehicle (UAV) was issued in Kabul and released to reporters covering an international conference on Afghanistan in the German city Bonn.

(Reporting by Missy Ryan; Editing by Myra MacDonald)