Aerial view Nantanz facility
© Reuters/handoutSatellite image shows general view of Nantanz Nuclear Facility after a fire in July, 2020.
A major explosion hit the Natanz uranium enrichment facility in Isfahan, central Iran on July 2. Tehran has since ruled out a missile or drone attack on the facility, but has also warned that if foreign involvement was discovered, there would be "consequences."

The July 2 explosion and fire at the Natanz nuclear facility was the result of sabotage, Behrouz Kamalvandi, a spokesman for Iran's Atomic Energy Organization, has said. "The explosion at Natanz nuclear facility was a result of sabotage operations, security authorities will reveal in due time the reason behind the blast," Kamalvandi said, speaking to al-Alam TV in an excerpt from an interview published Sunday.

Iranian investigators said they had determined the "main cause" of the blast two days after the incident, on July 4, but added that "security considerations" made it necessary to reveal the details about the "cause and nature" of the incident at a later date.

US and Arab media have speculated that the explosion was the result of a bomb blast, a cyberattack, or even an attack by Israeli F-35 jets. Israeli Defence Minister Benny Gantz dismissed claims of Israeli involvement, saying "not every event that happens in Iran is connected to us."

Iranian media have also speculated about alleged US or Israeli involvement, but authorities have so far refrained from making any formal allegations, only warning that there would be "consequences" if foreign involvement was discovered.

In late July, Iranian parliament National Security and Foreign Policy Committee chairman Mojtaba Zonnour said "internal elements" caused the blast, and added that drones and missiles were not involved. He did not elaborate on the nature of these 'internal elements.'

Situated about 30 km outside the town of Natanz, the Natanz nuclear facility is Iran's largest uranium enrichment facility. The plant was subject to a major cyberattack in 2010, when a Mossad mole allegedly installed the infamous Stuxnet malware programme into its computers in a sabotage attack supported by the CIA and Dutch intelligence.

A little-known group calling itself the 'Homeland Panthers' claimed responsibility for the July 2, 2020 blast.

Iran began gradually increasing its nuclear enrichment activities in May 2019, one year after Washington withdrew from the Iran nuclear deal and slapped Tehran with tough energy and banking sanctions. Since that time, the country has managed to increase enrichment from the 3.67 percent purity level outlined by the nuclear deal to about 4.5 percent. Tehran maintains it has no intention to pursue nuclear weapons. Its current enrichment levels are still well below the 80-90 level required to build a nuclear device.