No damage was incurred as part of the air defence test, according to Iranian media.
Tehran, Iran â€“ A loud explosion was heard near Iranâ€™s main nuclear facilities in Natanz, which have previously been targeted by sabotage attacks, but state media said it was part of a controlled test.
A major explosion and flash of light in the sky were reported around 8:15pm local time (16:45 GMT) on Saturday in Badroud, 20km (12 miles) from where the enrichment facilities are located.
Early reports speculated a surface-to-air missile defence system targeted a hostile object, most likely a drone.
Nournews, an outlet close to Iranâ€™s security forces, confirmed an air defence missile was fired and exploded in the sky, but said it was part of a rapid reaction test.
State television later confirmed this account, saying the test was part of drills that are regularly carried out under supervision from local air defence authorities. No damages were said to be incurred to the local area as part of the test.
The incident came as Israel has repeatedly threatened Iran with military action, pledging not to allow Iran to obtain nuclear weapons.
Iran has maintained that it will never seek a nuclear arsenal, contrary to Israel which has dozens of nuclear weapons. It has also blamed two attacks on the Natanz facility since last year, and another one earlier this year, on a centrifuge workshop in Karaj, on Israel, accusing it of â€œnuclear terrorismâ€.
Exposing the divide
Senior Iranian military officials regularly respond to Israeli threats by saying Israel does not dare attack as it will face a destructive response.
Top Israeli officials renewed their threats against Iran last week when Iran and the world powers party to its 2015 nuclear deal reconvened in Vienna in an effort to restore the accord that the United States unilaterally abandoned in 2018.
The seventh round of the talks, which ended on Friday, were not promising, further exposing the divide between Iran and the West. An eighth round is expected next week.
Israel has been the most vocal opponent of the deal, and fervently cheered former US President Donald Trump when he reneged on it, imposing harsh sanctions on Tehran.
Iranâ€™s nuclear programme has significantly advanced following the US withdrawal from the deal, and the country is now enriching uranium up to 60 percent, far higher than the 3.67 percent cap set in the accord.
As the Vienna talks were under way, the International Atomic Energy Agency (IAEA) announced that Iran has taken another step to progress its nuclear efforts, now enriching uranium to a purity of 20 percent at the underground Fordow facility.