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.
Over 100 drones have been fired at Israel by Iran, in addition to more than 100 unmanned aerial vehicles launched from Iran, the Israel Defense Forces said in a press conference Saturday.
Dozens of Israeli Air Force jets are also airborne and a joint operational plan was devised with U.S. Central Command, according to the IDF.
-ABC News' Jordana Miller and Dana Savir
An Israeli military source told ABC News that Iran has targeted military sites only -- civilian sites were not targeted.
The Israel Defense Forces also moved up its arrival estimate: The first drones will close in on Israel an hour earlier than expected, at 1 a.m. local time, 6 p.m. ET.
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.
