nytimes.com/2020/07/09/world/middleeast/iran-explosion.html
The precise location of Friday’s explosion was unclear, but analysts said there are several military and training facilities in the area.

An explosion rocked western Tehran early Friday, state media reported, causing widespread power failures in two residential areas and unnerving Iranians awakened for the third consecutive week by an early-morning blast.
The precise location of Friday’s explosion was unclear, but analysts said there were several military and training facilities in the area that could be the target of sabotage. A cause was not immediately determined.
“There are two underground facilities, a site associated with chemical weapons research and an unidentified military production site,” said Fabian Hinz, an Iran military expert and research associate at the James Martin Center for Nonproliferation Studies.
It was the third major explosion to have occurred in Iran between midnight and 3 a.m. over three consecutive weeks.