Thick black smoke billows from the blast site.

Firefighters from the petrochemicals plant near the port of Bandar Imam Khomeini and regional fire teams responded to contain the blaze and there were no injuries, IRIB said on its social media feed.

On the other hand, Iran on Friday blacklisted the US ambassador in Iraq and two other diplomats, following a similar move by the United States against Iran's envoy to Baghdad, the Iranian Foreign Ministry said.

Ministry spokesman Saeed Khatibzadeh said on Twitter that ambassador Matthew Tueller "has had a central role in coordinating terrorist acts in Iraq & beyond" including the assassination of Iranian commander Qassem Soleimani, killed by a U.S. missile strike at Baghdad in January.