A series of loud explosions are heard in central Israel as the military says it carried out intelligence-based strikes in Tehran.

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.

Iran launched dozens of ballistic missiles toward Israel on Friday night in retaliation for Israel's surprise attack early Friday. Israel struck at the heart of the Iran's nuclear program, killing several nuclear scientists as well as high-ranking military leaders, according to Israeli officials.