Iran Says Explosion at Natanz Nuclear Facility Was Drill

An explosion reported near Iran’s Natanz nuclear enrichment facility on Saturday was part of a controlled test, according to Iran state media.

The explosion and a flash of light was seen in the night sky about 20 kilometers, or 12 miles from the facility, which is mainly underground. A spokesman for the Iranian military told the official Fars news agency that the explosion was caused by an air defense missile fired as part of a drill to test the response to a possible attack.

The explosion comes as talks continue in Vienna between Iran and the world powers on curbing Iran’s nuclear program in exchange for sanctions reduction. Israel has been blamed for recent attacks on nuclear sites in Iran, including an April attack on Natanz.