Iran says its military forces have shot down an Israeli drone aircraft that had crossed into Iranian airspace and was flying near the Natanz nuclear facility.
In a statement on August 24, Iran's elite Revolutionary Guard said the "spy drone" was trying to approach the Natanz uranium enrichment site in central Iran.
The statement described the incident as "new adventurism" by Israel.
There was no immediate comment from Israeli officials.
Natanz is Iran's main uranium enrichment facility and houses most of Iran's known centrifuges, which are used to enrich uranium to a higher level.
Enriched uranium can be used to fuel nuclear power plants, but when enriched to a higher level it can also be used for nuclear weapons.
Israel fears Iran is using the facility to try to develop nuclear weapons, and has often threatened to attack Iran's nuclear installations.
Iran has reached a six-month interim agreement with six world powers in the so-called P5+1 group under which Iran suspended some of its nuclear activities in return for a partial lifting of international sanctions.
In July, that deal was extended by four months until November 24 to give the side more time to negotiate a final nuclear accord aimed at ending 10 years of tensions.
But the negotiating teams remain divided on the issue of how much uranium enrichment Iran should be allowed to carry out.
Countries in the P5+1 consist of the United States, Britain, France, Germany, Russia, and China.
The United States wants Tehran to cut its program by 75 percent.
But Iran wants to expand enrichment ten-fold by 2021, saying more enriched uranium is needed as fuel for its Bushehr nuclear power plant in the future.
Israel is a sworn enemy of Iran and opposes any agreement that would allow Tehran to keep part of its uranium enrichment program.
Iran has consistently denied it is trying to develop the ability to produce nuclear weapons.