CAIRO - Iranian authorities said no one was hurt in a blast early Saturday in Tehran, near the headquarters of Iranian radio and TV.
Iranian media said the explosion took place in a park, and that there was no damage.
Amateur video broadcast on Iranian opposition media showed Tehran firefighters trying to extinguish what looked like a major fire near a building in Mellat Park. Eyewitnesses said they heard a loud explosion before the fire broke out.
Video on social media showed broken glass and damaged windows at stores and shops near the park where the explosion took place.
Tehran's fire department spokesman told the official Iranian news agency, IRNA, that claims of a major fire and explosion were false. He said housewives often swear they had seen things but in reality were just imagining them.
The fire and explosion took place hours after a cyberattack on Iran's railway network disrupted trains and Tehran's subway. Iranian opposition media also reported that the transportation ministry website was knocked offline Saturday.
Adam Roosevelt, a national security analyst based in the United Arab Emirates, told VOA that he did not see any relationship between the fire and explosion in Tehran and the fire at a port facility in the UAE several days ago. Port officials, he said, told him that the fire there "was caused by [combustible materials] that were badly stored."
Roosevelt indicated that the cyberattack on Iran's railway network might have been masterminded by Israel, but more information was needed to prove it.
Both Israel and Iran have traded accusations in recent months over responsibility for a number of explosions and cyberattacks.
London-based Iran analyst Ali Nourizadeh told VOA that the fire and explosion overnight could have been much more serious than it finally turned out to be.
"A colleague of mine who works for [Iranian] radio and television told me the fire was not that huge but that the place [where it occurred] was very important" because of costly property damage that could have occurred, Nourizadeh said.
The Tehran fire and explosion occurred near a building housing the physics department of Shahid Beheshti University. An amateur video showed the aftermath of an alleged explosion and fire in what appeared to be a physics lab. VOA could not independently confirm the authenticity of the video.