Israel has launched blistering attacks on the heart of Iran’s nuclear and military structure, deploying warplanes and drones previously smuggled into the country to assault key facilities and kill top

Israel unleashed airstrikes across Iran for a third day and threatened even greater force as some Iranian missiles evaded Israeli air defenses to strike buildings in the heart of the country.

Israel warned hundreds of thousands of Tehran residents to evacuate a central district of the Iranian capital Monday, as the assault it began last week continued for a fourth day. Iranian strikes also targeted Tel Aviv and other cities.

Israel struck key Iranian nuclear sites to curb bomb development amid rapid uranium enrichment and rising tensions.

Revolutionary Guards Commander Hossein Salami reported killed. Fears of war rise as nuclear talks stall. See Iranian facilities before and after.

Israel says preemptive airstrikes against Iran's nuclear sites are underway, and it is bracing to intercept a wave of drones launched by Iran in retaliation.

The U.S. says it wasn't involved in the strikes on Iran, but three American officials told NBC News the U.S. is assisting in shooting down Iranian missiles and projectiles targeting Israel.