The incident is said to have taken place clost to the Tajrish Square, north of Tehran. Those at the scene say the cause of the explosion is unknown.
Newsweek reporter Tom O’Connor tweeted: “Following reports of an explosion at northern Tehran, Iran’s Tajrish Metro Station.”
Footage on social media showed plumes of black smoke rising high in the sky over the city, together with flames. Zillay Shah tweeted: “The cause of explosion is still not known.”
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