That surprise strike hit the heart of the Iran's nuclear program, killing several nuclear scientists as well as high-ranking military leaders, according to Israeli officials.The U.S. did not provide any military assistance or have any involvement in Israel's Friday strike,

The death toll is growing as Israel and Iran exchanged missile attacks for a third consecutive day on Sunday, and Israel is warning that worse is to come.

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