Part 1: Mysterious Explosions Rock Iran

Beginning in June 2020, Iran experienced a notable string of explosions, fires and industrial accidents. The damaged sites included Iran’s nuclear facility in Natanz, a missile plant in Khojir, the power grid in Shiraz and a chemical plant in Mahshahr. The most destructive incident was an explosion at the main uranium enrichment site in Natanz, which set back Iran’s nuclear program by months. On June 26, a similar incident ripped through Iran’s largest missile production plant near Tehran. Residents living in the capital city saw a bright orange glow lighting up the skyline.

On September 6, Iran confirmed that the Natanz incident was sabotage and claimed that security officials had identified the culprits. “The aim of those that sabotaged the facility, was to damage the production of enrichment material but they failed, our current production has not been damaged or halted,” said Behrouz Kamalvandi, spokesperson for the Atomic Energy Organization of Iran. 

The government played down nearly all of the other 19 incidents as accidents; they blamed gas leaks or mechanical failures. But hardliners and state media outlets accused the United States and Israel of sabotage at the Natanz nuclear site. Western media outlets alleged that Israel may have been behind some, but not all, of the incidents. One account claimed a bomb was planted in Natanz. Iran threatened retaliation if either country was found to be responsible. "We reserve the right to legitimate defense and proportional and appropriate response to the aggression and harm against our country in the face of cyber and non-cyber attacks," Foreign Ministry Spokesman Seyyed Abbas Mousavi told reporters on July 23. 

  • On June 26, a fire at the Shiraz power station caused extensive blackouts.
  • On June 26, an explosion went off at the Khojir missile plant near Tehran. Iran said that the blast was caused by a gas leak at the Parchin military base, but satellite imagery proved that Khojir, not Parchin, was damaged. 
  • On June 30, an explosion at the Sina Athar medical clinic in northern Tehran killed 19 and injured six.
  • On July 2, an explosion caused significant damage to a centrifuge factory at the Natanz nuclear enrichment site
  • On July 4, a fire damaged the Zargan power station in the western city of Ahvaz. The station provides power to oil-rich Khuzestan province.
  • On July 4, a chlorine gas leak at Karoun petrochemicals plant in Mahshahr, on the Gulf coast, injured dozens of workers.
  • On July 7, an explosion at a factory in Baqershahr killed two people. The explosion occurred at an industrial park near Tehran.
  • On July 10, an explosion in western Tehran caused blackouts in two residential areas.
  • On July 12, a fire broke out at the Shahid Tondgooyan petrochemical facility in Mahshahr.
  • On July 15, seven ships caught fire at the southern port of Bushehr.
  • On July 19, an explosion at the Isfahan power station caused a two-hour blackout.
  • On October 11, an explosion at a market place in Ahvaz killed five people. 

Key for map

Click on icons for more details. Click on top-left for list of incidents. Click on top-right to enlarge.

There were other mysterious incidents. Two other fires erupted on July 11 in Tehran and July 13 near Mashhad; the government blamed both of them on faulty gas cylinders. On July 12, a fire at a petrochemical plant in Mahshahr was blamed on an oil leak. On July 14, a fire erupted at an aluminum factory in Lamerd. On July 18, an oil pipeline exploded in Ahvaz, and on July 19, a fire erupted at a cellophane factory in northwest Iran. On July 24, a brush fire erupted in Tehran near a military housing complex, and on July 28, a fuel tank explosion in Iran's Kermanshah province destroyed several vehicles.

Evidence linking the incidents was scant. But Israel has made no secret of its determination to block Iran’s nuclear program. Mossad operatives have allegedly assassinated at least four Iranian nuclear scientists between 2010 and 2012. In January 2018, Israel stole 55,000 pages of documents detailing Iran’s prior work on a nuclear weapon—most before 2003—in a daring raid in Tehran. Israel has allegedly worked in tandem with the United States to develop and carry out cyberattacks, such as the Stuxnet and Flame computer viruses, that target Iran’s nuclear and oil infrastructure. 

Israeli officials pushed back on accusations of a coordinated campaign but did not deny involvement in the Natanz explosion. “Some choose to be suspicious of us all the time,” Israeli Defense Minister Benny Gantz said. “Yet not every incident that unfolds in Iran is connected to us.”

The incidents also coincided with a Yahoo News report that President Trump had allegedly granted the CIA more authority to conduct cyberattacks on Iranian civilian infrastructure, such as petrochemical plants. "Given Mr. Trump’s order, it would be perfectly natural to say that the US government will be the prime suspect for any cyberattack against Iran hereafter, unless the contrary is proved," Mousavi said, although he denied that the incidents were caused by cyberattacks. However, Iran's atomic energy agency later said that security officials had thwarted "many cyberattacks" on nuclear and industrial infrastructure. 

The United States has also reportedly sabotaged Iran’s nuclear and missile programs, mainly through cyberattacks. In 2006, President George W. Bush initiated a covert campaign to target Iranian nuclear capabilities, codenamed Operation Olympic Games, according to Western media. The Obama administration reportedly expanded the program to use cyber weapons on Iran’s nuclear enrichment sites. In 2010, the Stuxnet virus, allegedly developed by the United States and Israel, crippled the Natanz facility and set back its uranium enrichment capabilities by months. Under President Trump, the United States has allegedly introduced faulty components into Iranian ballistic missiles and hacked a computer system that launched missiles.


June 26: Shiraz power station

What happened? A fire erupted at the Shiraz power plant. The blaze caused a blackout that left 1.2 million people without electricity for several hours. Firefighters extinguished the blaze and restored power to the city.

What did Iran say? The fire marshal of Shiraz said the fire was caused by an explosion but offered few other details. State authorities later claimed the fire was due to a transformer malfunction.

Why is it significant? Shiraz is home to a major military base. The incident also occurred just hours before a major explosion at the Khojir missile plant.

Claims of sabotage: No major claims.


June 26: Khojir missile plant

What happened? An explosion hit a missile production plant at Khojir, 12.5 miles (20 kilometers) east of Tehran. The plant produces solid fuel for Iran’s Fajr rockets and Sajil ballistic missiles, according to the Begin-Sadat Center for Strategic Studies. Commercial satellite imagery showed a scorched hillside near the facility, but the main building appeared undamaged. The blast rattled homes in Tehran. Residents of the capital city posted footage of a bright orange skyline on social media.

What did Iran say? Iran’s defense ministry claimed the explosion was caused by leaking gas tanks at the Parchin military base. Hours after the incident, state TV broadcasted footage of charred gas tanks purported to have caused the explosion. But satellite footage revealed that the explosion went off at Khojir, not Parchin. Iranian military officials did not rule out a cyberattack. “It has been mentioned that the incident was caused by hacking the center's computer systems,” Brig. Gen. Gholamreza Jalali said. “But until we come to a conclusion on the dimensions of this incident and the claim, we cannot comment.”

Why is it significant? “Numerous tunnels, some suspected of use for arms assembly” were constructed under Khojir, according to the Center for Strategic and International Studies. In 2019, the U.S. Defense Intelligence Agency (DIA) reported that Iran hides most of missile development and production in underground facilities. “Iran has the largest underground facility (UGF) program in the Middle East,” the DIA said. 

The Khojir missile plant is also close to Parchin, a military base where Iran has long been suspected of hiding nuclear experiments. In 2012, Iran blocked access to nuclear inspectors from the International Atomic Energy Agency (IAEA). Tehran granted the IAEA access only after the Joint Comprehensive Plan of Action (JCPOA) was agreed to in 2015. Inspectors found faint traces of uranium particles at the base.

Claims of sabotage: Al Jarida, a Kuwaiti newspaper, claimed that an Israeli stealth fighter had hit the missile plant; it cited a “senior security source.” Israel denied responsibility for the incident. Israeli foreign intelligence services told the New York Times they had not concluded whether the explosion was the result of an accident or intentional sabotage.


June 30: Sina Athar medical clinic

What happened? An explosion rocked the Sina Athar medical clinic on Shariati street in northern Tehran. The blast killed 19 people – 15 women and 4 men – and injured six. Videos posted by passersby on social media showed firefighters struggling to put out the blaze. The semi-official Iranian Students News Agency released photos that showed a thick plume of smoke over the destroyed clinic.

What did Iran say? Hamidreza Goudarzi, the deputy governor of Tehran, claimed that a gas leak caused the explosion. Jalal Maleki, spokesperson for the Tehran fire department, said that gas canisters in the clinic’s basement caught fire and spread the destruction. Some victims “were in upper floors in operation rooms, who were either patients being operated on or those with them,” Maleki said. “They unfortunately lost their lives due to the heat and thick smoke.”

Why is it significant? The blast occurred four days after the explosion at the Khojir missile plant, which Iran also attributed to a gas leak. Tehran’s police chief denied rumors that the fire had been the result of sabotage, but police officers interrogated the Sina Athar’s director general and three other clinic officials after the blaze was extinguished.

Claims of sabotage: No major claims.


July 2: Natanz nuclear enrichment facility

What happened? An explosion caused extensive damage to Iran’s main nuclear enrichment site at Natanz. The blast damaged a factory producing advanced IR-4 and IR-6 centrifuges that could enrich uranium faster than the IR-1 centrifuges allowed under the 2015 nuclear deal. The damage set back the country’s nuclear program by months, Iran conceded. “It’s possible that this incident will slow down the development and expansion of advanced centrifuges,” said Behrouz Kamalvandi, spokesman for the Atomic Energy Organization of Iran.

What did Iran say? Iran initially claimed that the incident was an accident that caused minimal damage. “There was no radioactive material in it and there were no personnel,” Kamalvandi said. But hours after the explosion, the IRNA news agency accused Israel and the United States of crossing “red lines” and threatened retaliation. Iran’s top civil defense official warned that Tehran would retaliate if intentional sabotage was proven. Javad Karim Qoddousi, a member of parliament and former IRGC commander, said that the blast came from inside the building. He and other MPs investigated the site and concluded there had been a "security breach."

Why is it significant? The Natanz facility’s central role in the Iranian nuclear program has made it a target in the past. In 2010, the Stuxnet computer virus – allegedly developed by the United States and Israel – damaged hundreds of centrifuges at the Natanz facility. But the Revolutionary Guards reportedly ruled out cyberattacks as the cause of the attack.

Claims of sabotage: Israel reportedly planted a bomb in the facility, The New York Times and the Washington Post reported; both cited a Middle East intelligence source. Israeli defense officials did not deny the specific claims made by the Times and Post but played down media reports linking the Jewish state to other mysterious incidents. “Some choose to be suspicious of us all the time,” Defense Minister Benny Gantz said. “Yet not every incident that unfolds in Iran is connected to us.”

A group calling itself “Cheetahs of the Homeland” – self-described as dissidents operating within Iran’s security establishment – claimed responsibility for the explosion. The group sent BBC Persian a statement claiming responsibility hours before Iranian state news reported the explosion at Natanz. But there was little other corroborating proof linking the unknown group to the incident. “There is also the possibility that the email was an elaborate attempt to mislead us as to who was behind the attack, and could actually be the work of foreign agents posing as opponents of the regime in Iran,” BBC Persian wrote.


July 4: Zargan power station

What happened? An explosion went off at the Zargan power station in Ahvaz in western Iran. The blast damaged a transformer and caused partial outages in the city. Video posted online showed thick black smoke rising over the plant. Firefighters struggled for more than two hours to contain the inferno.

What did Iran say? Ebrahim Ghanbari, the head of Ahvaz fire and safety services, said that a “transformer explosion” caused the fire, according to the IRNA news agency. A spokesperson for the electricity industry subsequently said that a faulty connection – rather than an explosion – had caused the fire. 

Why is it significant? The explosion was the second to hit an Iranian power plant in less than two weeks, after the June 26 blast at the Shiraz power station. The Zargan power station supplies power to all of Khuzestan province, home to many of Iran’s Arab minority population. The blast occurred the same day and in the same province as a major chemical gas leak.

Claims of sabotage: No major claims.


July 4: Karoun petrochemical plant

What happened? A chlorine gas leak at the Karoun petrochemical plant in Mahshahr hospitalized 70 workers. A ruptured pipe caused the leak, according to the IRNA news agency. The incident occurred at a facility near Bandar Imam Khomeini, a port city on the Persian Gulf named after Ayatollah Ruhollah Khomeini. Videos obtained by Al Arabiya showed a yellow gas in the air above the plant, as well as coughing workers being treated at the hospital.

What did Iran say? Massound Shabanlou, spokesperson for the plant, said that workers suffered “slight injuries” due to chlorine inhalation and that all but two had been released.

Why is it significant? The leak occurred on the same day and in the same province as a blast at the Zargan power station. The incident occurred in the oil-rich Khuzestan province.

Claims of sabotage: No major claims.


July 7: Baqershahr factory

What happened? An explosion killed two and injured three at a factory in Baqershahr, 14 miles (23 kilometers) south of Tehran. The blast occurred before dawn in an “industrial zone.” It was powerful enough to destroy the walls of a nearby building. Users on the messaging app Telegram reported that the loud explosion had  “terrified” locals.

What did Iran say? Iran blamed “human error” for the blast. “The explosion [was] caused by some workers’ negligent handling of oxygen tanks,” Amin Babai, a local official, told Reuters.

Why is it significant? Iran did not detail what the factory produced.

Claims of sabotage: No major claims.


July 10: West Tehran explosion

What happened? An explosion went off western Tehran and caused power failure in two residential areas, state media reported.

What did Iran say? Leila Vaseghi, the governor of Qods city, denied that there was an explosion; she said it was only a temporary failure at a power plant. But the mayor of a nearby town said that the explosion occurred “at a factory making gas cylinders.” 

Why is it significant? The explosion was the third major explosion to happen near Tehran between midnight and 3 a.m. since June 25. The blast was near an underground chemical weapons research facility and other military production sites.

Claims of sabotage: No major claims.


July 12: Shahid Tondgooyan petrochemical facility

What happened? A fire briefly erupted at a petrochemical facility in Mahshahr in Khuzestan province.

What did Iran say? Mohsen Beyranvand, the county governor, said that an oil leak caused the fire and was put out in less than ten minutes.

Why is it significant? The incident was the second to affect a petrochemical plant in Khuzestan after the July 2 chlorine leak at Karoun petrochemicals.

Claims of sabotage: No major claims.


July 15: Bushehr port

What happened? At least seven wooden ships docked in Bushehr port in southern Iran caught fire. The blaze lasted for five hours. Trucks from the Iranian navy and Revolutionary Guards helped put out the fire.

What did Iran say? Jahangir Dehghan, director general of local crisis management at the port, said that the cause of the blaze was unknown. He added that high winds had contributed to the fire’s spread.

Why is it significant? The fire was the first incident of its kind targeting a port.

Claims of sabotage: No major claims. 


July 19: Isfahan power plant

What happened? An explosion went off at a thermal power plant in Isfahan. The blast cut power for two hours.

What did Iran say? The power company said that a “worn-out transformer” had exploded at 5am. There were no casualties, according to local officials.

Why is it significant? The explosion was the third incident at a power station after the July 4 explosion at Zargan and the June 26 fire at Shiraz.

Claims of sabotage: No major claims.


October 11: Ahvaz marketplace

What happened? An explosion went off at a marketplace in Ahvaz. The blast destroyed a building and several shops. Five people were killed and nine were injured. 

What did Iran say? The cause of the explosion was gas, the Ahvaz fire department said.

Why is it significant? The explosion was the first to cause casualties in months.

Claims of sabotage: No major claims.


Photo Credit: Firefighters at Ferdowsi Square via Fars News Agency (CC BY 4.0)
Some of the information in this article was originally published on July 10, 2020.