The IDF says it struck military targets of terrorist organizations in Gaza.
Israel launched a retaliatory strike against Iran early Friday morning local time, a senior U.S. official told ABC News.
The strike followed Iran's attack on Saturday, when Tehran sent a volley of more than 300 drones and missiles toward targets in Israel, according to Israeli military officials. All but a few were intercepted by Israel and its allies, including the United States, officials said.
Iran's weekend attack came more than six months after Hamas terrorists invaded Israel on Oct. 7, after which the Israeli military began its bombardment of Gaza.
Israeli officials said the country's Iron Dome defense system endured a big test from Iran's attack on Saturday, intercepting 99% of the 300 "threats of various types" thrown at it.
Iran's Islamic Revolutionary Guard Corps, according to Israel Defense Forces spokesperson Daniel Hagari, launched 170 unmanned aerial vehicles (UAVs), more than 120 ballistic missiles and more than 30 cruise missiles in the attack.
Hagari said "99% of the threats launched towards Israeli territory were intercepted -- a very significant strategic achievement."
Hagari said the attack resulted in only one known Israeli casualty, a 7-year-old girl who was severely injured when she was struck by shrapnel apparently from an intercepted missile.
A senior U.S. official told ABC News they now think there will be anywhere from 400 to 500 drones and missiles launched at Israel from Iraq, Syria, southern Lebanon and the Houthis, but that the bulk will be launched from Iran.
The drones are the same kind used in Ukraine.
Israeli aviation authorities say they are closing the country's airspace to all flights at 12:30 a.m. local time, 5:30 p.m. ET.
Flights would be affected and advised travelers to check with their airlines for changes.
Iranian state television also announced that Tehran had launched an attack toward Israel. Iraq's state news agency quoted Transportation Minister Raqqa Saadawi as saying the country's airspace was closed.
Before the attack was announced, a FlyDubai flight from Dubai in the United Arab Emirates to Tel Aviv, Israel, turned around as it was over Saudi Arabia, flight-tracking data showed. United Airlines also canceled a Saturday flight from Newark to Tel Aviv and the return flight.
Iran's Islamic Revolutionary Guard Corps announced that it has launched extensive missile and drone operations against targets in Israel, according to Tasnim, the Iranian news-agency affiliated with the branch of Iran's armed forces.
An Israeli source also confirmed to ABC News that Iran fired cruise missiles from Iraq as well.
In a post on X, the Iranian Foreign Minister said "necessary warning has been given to America."
The U.S. will try to help Israel intercept everything possible -- not just those that pass over U.S. ships -- despite Iran informing the U.S. that they should stay out of it, a senior U.S. official confirmed to ABC News.
In the coming hours the U.S. expects missile launches from Iran and southern Lebanon -- and maybe even the Houthis -- as well as drones, which take longer to reach target. The Iranians are trying to overwhelm the Israeli air defenses with drones and missiles coming in at different altitudes, speeds and directions -- but hitting targets at the same time, according to the official.
While the U.S. expects that most of these will be intercepted -- upwards of 85% -- the fear is that if any Israeli lives are lost, the Israeli response will be much bigger.
The target is believed to be three military bases, especially one where F-35s are kept. While these bases are relatively remote, there are towns nearby and these Iranian weapons are not completely accurate.
The U.S. has no doubt Israel will respond whether lives are lost or not. And that Iran itself will be targeted.
-ABC News' Martha Raddatz
