An explosion from a gas leak in a medical clinic in northern Tehran killed 19 people, The Associated Press reported on Tuesday, citing Iranian state TELEVISION.
Authorities initially said 13 people were dead, but Jalal Maleki, spokesman for the Tehran Fire Department, later told state TV that the toll had risen up to 19.
State-run IRNA news agency also quoted Maleki as saying the dead included 15 women and four men. Maleki added that firefighters had rescued 20 people.
Video posted online did actually show multiple explosion and thick black smoke rising from the flames.
Hamidreza Goudarzi, deputy Tehran governor, told state TV a leak from medical gas tanks in the building was the cause of the explosion and fire.
People in nearby Tajrish Bazaar rushed to the scene, impeding a rescue operation, authorities said. Videos on social media showed people gathered outside of the building.
State TELEVISION said there may be more explosions because there have been a number of oxygen tanks remaining in the medical center.