Huge explosion in Isfahan, Iran - home to nuclear weapons program (plus insta-poster!, updated)

UPDATE 11/30: Confirmation that the explosion was at a nuclear facility. New blog post here.

---

FARS News is reporting on a huge explosion in Isfahan, Iran. No details yet.

Isfahan hosts a Nuclear Technology Center, a Uranium Conversion Facility and a Zirconium Production Plant that helps make alloys for nuclear reactors.

According to the article, it happened at 2:40 AM.

For the occasion, a poster:

UPDATE: The FARS story has disappeared. Here's what the autotranslate looked like before it went down the memory hole:

Twitter updates/rumors:

A BBC reporter tweets his father in Isfahan heard the explosion.

Israel's Channel 10 reports that an explosion was at Shahab 4 ballistic missile site; unclear if it is the same one or where they got the information from.

Second Iranian news source confirms it, unclear if it was 2:40 AM or PM.

And another confirmation.

Iranian tweeters are all saying it was either an arms depot or an ammunition depot.

Isfahan's governor is now claiming that it was from a "military exercise."

Deputy governor says, "I dunno."

I've seen a few stories saying it happened near the gate to Shiraz University.

Mehr claims it was from a gas station explosion.

PressTV quotes officials denying the story altogether.