Photographs posted on Russian Telegram channels showed a shattered entrance to a building littered with rubble and two bodies lying in the blood-stained snow.
Israel can strike Iran in a "forceful and sophisticated manner. If needed, we will not hesitate to act," Gallant was cited as saying.
All of this makes the next six weeks until US Inauguration Day a wide-open playing field where getting closer to a mini-nuclear deal or to an escalating nuclear conflict are both possibilities.
France's intelligence head made rare comments on Iran's nuclear capabilities.
European and Iranian officials meet in Geneva to discuss nuclear program and regional tensions before Trump takes office in January.
The countries raised their concern with the Islamic Republic's announcement of its further nuclear program expansion, which they explained has "no credible, peaceful rationale."
The board also requested a "comprehensive" report to pressure the Islamic Republic into new nuclear talks.
The source said that "this is the first time in many years that two conditions are present" regarding attacking Iran's nuclear program, namely that such an attack "is necessary...and is possible.
The sophisticated equipment destroyed in the attack was essential for shaping and testing plastic explosives that encase uranium in a nuclear device.
The strike dealt a severe blow to Iran’s nuclear development efforts, according to the officials cited in the report.