An Iranian nuclear scientist says two of his country's nuclear facilities were attacked last month, in separate explosions that he blamed on sabotage. Fereydoon Abbasi, the head of the Atomic Energy Organization of Iran, revealed that two different locations were targeted by explosions on August 17, one day before U.N. inspectors came visit the sites. One was at the well-known Natanz nuclear facility and the other was at Fordow, a deep underground uranium enrichment site believed to be heavily protected against a possible airstrike.

Abbasi claimed the attacks were acts of sabotage, and while he did not accuse the United States or Israel of being behind them, the two countries are believed to be waging a covert war against the Iranian nuclear program, using both cyberwarfare and assassinations to disrupt their ability to build a nuclear weapon. Abbasi himself survived an assassination attempt while driving in his car two years ago. The explosions knocked out power lines to centrifuge machines, a tactic that has been used to destroy such machines at Natanz in the past. He also claimed that the International Atomic Energy Agency has been infiltrated by “terrorists and saboteurs,"

If Abbasi's claims are true, it would show that the covert war is still ongoing and that the U.S. and Israel may still be hoping to destroy the Iranian nuclear program from within, rather then relying on bombing or  traditional military force. Sites like Fordow have been constructed deep underground to protect them from war planes, leading some to argue that an Israeli military strike on the country would have little effect on Iran's nuclear ambitions.