Tehran: The unmanned US spy plane was deep inside Iran's airspace, flying over an eastern town famous for Persian carpets and saffron when it was downed by Iranian armed forces, state radio reported yesterday.

The report said the stealth-version of the RQ-170 drone was detected by Iranian forces over the eastern town of Kashmar, some 225km from the border with Afghanistan.

"The US smart plane was captured by Iranian anti-aircraft units somewhere in the sky over Kashmar in the east of the country," the radio said. It did not speculate as to why the drone flew over the town, which lies in an agricultural area known for the production of saffron and Persian carpets.

The radio added that Iran will "soon" broadcast video footage of the downed drone.

Iran first reported the downing on Sunday but did not say when the incident happened. At the time, the official Irna news agency said Iran's armed forces had shot it down — a claim later rejected by US officials who said the drone crashed over the weekend but that there was no indication it had been shot down.

Classified

Meanwhile, US officials, speaking on condition of anonymity to discuss classified information, have said the drone had spied on Iran for years from a US air base in Afghanistan.

According to these officials, the US built up the air base in 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.