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.

The death toll grew Sunday as Israel and Iran exchanged missile attacks for a third consecutive day, with Israel warning that worse is to come. Israel targeted Iran’s Defense Ministry headquarters in Tehran and sites it alleged were associated with Iran’s nuclear program,