Explosion in western Iran injures more than 200
The blast struck late Friday in Chardavol county in Ilam province, the news agency said.
The head of the province's medical university, Mohammad Karimian, told IRNA driver "carelessness" was suspected.
The incident is the latest in a series of fires and explosions that have hit military and civilian sites across Iran since June.
This isn't the first explosion to hit Iran.
In July an explosion hit a power plant in the central Iranian province of Isfahan on Sunday, state news agency IRNA reported, saying it was over faulty equipment and caused no casualties.
A "worn out transformer... at Isfahan's Islamabad thermal power plant exploded at around 5:00 am today," the managing director of Isfahan's electricity company Said Mohseni told the agency.
The facility returned to normal working conditions after about two hours and Isfahan's power supply was uninterrupted, he added.
Two explosions rocked Tehran in late June, one near a military site and the other in a health centre, the latter killing 19 people.
Fires or blasts also hit a shipyard in southern Iran last week, a factory south of Tehran with two dead and the Natanz nuclear complex in central Iran earlier this month.
Iranian authorities called the Natanz fire an accident without elaborating and later said they would not reveal the cause, citing "security reasons".
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The string of fires and explosions have prompted speculation in Iran that they may be the result of sabotage by arch enemy Israel.
Israel accuses Iran of seeking to acquire a nuclear bomb while Tehran insists its nuclear programme is entirely peaceful.