Iran's Transportation Ministry said that its computer systems and website were affected by a cyberattack on July 10.
The alleged attack took down the ministry's website and links associated with it, the ministry reportedly said in a statement.
The disruption began before noon; the sites were still down five hours later.
It was the second cyberattack to hit the ministry's computer systems in two days.
Iran's rail system reportedly came under cyberattack on July 9, with a system designed to track trains failing and hackers posting false messages on display boards across the country claiming trains had been delayed or canceled.
The country's telecommunications minister, Mohammad Javad Azari Jahromi, warned on July 10 about possible cyberattacks though ransomware.
Iran has been targeted by numerous cyberattacks in recent years, including an attack on government infrastructure in 2019.