Israel’s unprecedented attacks on Iran had at their core an elusive and high-risk goal: eradicating the country’s controversial nuclear program.

The two powers have been exchanging barrages since Israel attacked Iran and killed many of the country’s top military leaders and scientists.

A natural-gas refinery in southern Iran suffered an explosion Saturday after what authorities said was an Israeli drone attack, according to the Iranian defense ministry news agency Defa Press. Israel has launched dozens of strikes at Iran's nuclear and military facilities since Friday.