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 launched blistering attacks on the heart of Iran's nuclear and military structure Friday, deploying warplanes and drones previously smuggled into the country to attack key facilities and kill top generals and scientists -- a barrage it said was necessary before its adversary got any closer to building an atomic weapon.