An object exploded Saturday in the night sky near the Iranian nuclear facility in the town of Natanz, with state television saying it was a missile exercise.

Natanz's governor said there were no casualties and that a report would be released Sunday. Initial reports said the explosion was a defensive strike against a hostile drone, but officials have denied this. Instead, they say it was a drill to test how quickly their defense missiles work. Locals reported a loud sound and a bright flash at around 9 p.m.

The incident occurred while the United States and Iran are in the midst of talks over nuclear sanctions, which the White House admitted Wednesday were not progressing as hoped.

#BREAKING Iranian security officials tell state TV that the explosion was a test of the rapid reaction of the country's missile defense system. They said the blast was a result of the controlled explosion of the missile fired by the air defense system

— Reza Khaasteh (@Khaaasteh) December 4, 2021