Iran and Israel traded air raids and ballistic missile barrages overnight and into the evening Sunday, with neither side showing any inclination to back down from an escalating grudge match between the two longtime enemies.

Iran has two known underground nuclear enrichment sites, the one Israel attacked on the first day of its assault at Natanz, and another at Fordo. Both sit south of Tehran in central Iran, but Fordo has long been the Iranian nuclear facility of most concern to international monitors and experts.