Just before Iran and the International Atomic Energy Agency (IAEA) are scheduled to meet in Tehran on Tuesday, a mysterious explosion lit up the sky over Tehran.  It apparently happened at a military range that the west suspects was used to test triggers for potential nuclear weapons.

Iranian officials deny that an explosion had taken place at the expansive Parchin military site east of the capital.  However, witnesses saw an enormous orange flash on Sunday night at around 11:15 PM local time, and it clearly came from that direction.  Witnesses also said that all trees in a hundred-yard radius of two villages on the outskirts of Parchin had been burned.

The semi-official Islamic Republic News Agency said only that a fire “broke out in an explosives producing factory in eastern Tehran,” neglecting to include the name Parchin.  Two people were killed.  The report did not specify the cause of the incident.

It’s long been believed that Israel and the United States have carried out a series of sabotage missions against the Parchin site, including:  Crippling computer viruses; the assassination of nuclear scientists; and a series of mysterious explosions that have killed high-level targets and damaged facilities.