Gas stations across Iran were hit by disruptions on December 18, with Oil Minister Javad Owji saying that foreign interference was the probable cause.
Owji told state television on December 18 that about 70 percent of the country's gas stations were hit, adding that it was possible the disruption was the result of "outside interference."
Owji later said 1,650 gas stations out of the 3,800 supervised by his ministry were operational.
A hacker group known as Gonjeshke Darande, or Predatory Sparrow, which Tehran accuses of having ties with Israel, claimed responsibility for the disruption.
"We, the Predatory Sparrow, have again targeted the Islamic republic's national fuel supply system with a cyberattack," the group claimed on social media.
The hacker group's claim could not be independently verified.
Iran's Civil Defense Agency, which is responsible for the country's cybersecurity, said it was still considering all possible causes for the disruptions, including hacking and infiltration, but cannot yet confirm any claims.
Reza Navaz, a spokesperson for Iran's fuel station owners, described the incident as a "software glitch in the smart fuel system" and said technicians are looking into the problem.
He urged motorists who are not in critical need of fuel to refrain from driving to the stations to avoid congestion.
Jafar Salari-Nasab, the CEO of the National Iranian Oil Products Distribution Company, acknowledged the widespread disruption and asked the public for patience.
Iran has faced a number of cyberattacks in recent years. It has also faced accusations that it has orchestrated cyberattacks on rival nations, including Israel and Saudi Arabia.
In June, Khuzestan Steel Company, one of Iran's biggest steel companies, was forced to halt its operations after being targeted by a cyberattack.
In 2021, an attack on the electronic-transaction system used to distribute subsidized fuel paralyzed more than 4,000 gas stations across the country and resulted in long lines of angry motorists unable to use their government-issued smart cards.
Iran was also targeted about a decade ago by the Stuxnet computer worm, which is widely believed to have been engineered by the United States and Israel to sabotage the country’s nuclear program.