said the drone came down over eastern Iran, hundreds of miles from the cluster of nuclear sites in central and north-western Iran. Some said it came down close to the city of Kashmar in Khorasan province; others that it was recovered in the Tabas desert to the south-west.

The Iranian ambassador to the United Nations, Mohammad Khazaei, told CNN, “It was brought down somewhere in about some 150 miles or 250 kilometers deep into the Iranian territory in the province of Khorasan in the northern city of Tabas.”

The Tabas desert is a remote region used by the U.S. military in 1980 as a staging area during the abortive attempt to rescue the hostages at the U.S. embassy in Tehran.

According to experts who follow Iran’s nuclear program, this part ofthe country is not known for nuclear facilities. More than a decade ago there were reports that Iran had developed an enrichment facility with North Korean help in the Tabas Desert. But its existence was never confirmed, and an official at the International Atomic Energy Agency said its delegations had not been to the area.

David Albright, the president of the Washington-based Institute for Science and International Security (ISIS), expressed doubts that North Korea would have shared centrifuge technology with Iran at a time it was developing its own enrichment facilities.

The area is known for its uranium mines. which Iran is under no obligation to subject to international inspection. The main mine is at Saghand in Yazd province, to the south-west of the Tabas desert. According to ISIS, it