Iranian state TV said that Oil Ministry officials were convening an "emergency meeting" to solve the technical issues amid cyberattacks, targeting gas stations.
"The Supreme National Security Council confirmed that there has been a cyberattack against the petrol distribution computer system", the television station IRIB said. "Technical experts are fixing the problem and soon the refuelling process... will return to normal".
The disruptions occurred nearly two years after widespread protests hit the country due to a major increase in fuel prices.
No group has claimed responsibility for the attack so far.
Multiple posts on social media, purportedly showing people in massive queues at petrol stations as they are struggling to refuel have since appeared.