The blast is said to have taken place close to the Tajrish Square, north of Tehran, with suggestions it was centred on the Sina Athar medical facility. Eyewitnesses said the cause of the explosion was unknown, with the Khabaronline news site suggesting 13 deaths and several more injured. 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.
Midway through the clip, there is a second, very loud blast.
Zillay Shah tweeted: “The cause of explosion is still not known.”
Iran explosion: Footage shows flames shooting to the sky
Footage apparently showing the building in flames
Journalist Kian Sharifi posted: “A spokesman for the fire department confirms to Fars news that a health care centre is on fire in northern Tehran, saying ‘people may be trapped inside’.”
Semi-official Iranian news agency ISNA has also reported on the explosions, without citing any additional information.
Jalal Maleki, the Tehran Fire Department spokesman, told the Tasnim news agency a fire had broken out in a medical clinic in north Tehran, with firefighters sent to the scene.
Footage showed thick black smoke over Tehran
The head of the Tehran Emergency Center, Peyman Saberian, initially told the Fars news agency three people had been injured.
The explosion was caused by a gas leak, Tehran Deputy Governor Hamid Reza Goudarzi told state TV.
Another Twitter user, Jahangir, tweeted footage purportedly showing people trapped in the building, commenting: “I CAN’T BREATH yells one of the entrapped people in a MRI center near Tajrish square, northern Tehran after at least 2 explosions in the building shocked the city.
Midway through the explosion there is a second, very loud blast
Another view of the scene
“Fire Station is less that 1 km away, yet no sign of fire brigades, at least in this location.”
Hossein Ghanzankari tweeted a clip of a person being lifted into an ambulance, commenting: “Iranian news agency says patients are being evacuated from the medical building in north of Tehran after tonight’s explosion”.
The explosion comes days after another blast close to a sensitive military site near Tehran last week.
Footage apparently shot outside the medical facility
Speaking on state television, a defence ministry spokesman claimed it was caused by a tank leak at a gas storage facility.
However, there was also speculation that it was an accident at a defence site belonging to the Islamic Revolutionary Guard Corps.