A massive fire broke out at a state-owned refinery to the south of Tehran, Iranian state media reported, sending thick plumes of black smoke over the city.
There were no immediate reports of casualties.
The fire is believed to have struck a liquefied gas line of the capital’s Tondguyan refinery, Mansour Darajati, the director-general of Tehran’s crisis management team, told state TV late on June 2.
It wasn't immediately clear what started the blaze.
Firefighters have been dispatched to the area, according to the IRNA state news agency.
The fire at the refinery occurred hours after the Iranian navy's largest vessel caught fire under unknown circumstances and later sank in the Gulf of Oman.