Iran launches attack on Israel: What is the Iron Dome?

Iran unleashed an attack on Israel Saturday night, sending more than 300 uncrewed drones and missiles toward targets throughout the country, Israeli military officials said.

All but a few were intercepted by Israel and its allies, including the United States, officials said.

The Pentagon said April 2 that Israel was behind an airstrike in Damascus, Syria, that killed seven people, including a top Iranian commander, even though Israel has not claimed responsibility for the attack.

The Saturday attack on Israel came more than six months after Hamas terrorists invaded the country on Oct. 7, 2023, after which the Israeli military began its bombardment of the Gaza Strip.

The Iranian attack resulted in only one known Israeli casualty, a girl who was severely injured when she was struck by shrapnel apparently from an intercepted missile, Israel Defense Forces spokesperson Daniel Hagari said Sunday. The hospital said Sunday the girl was 7 years old and remained in "difficult and unstable" condition. "She suffers from a very serious head injury and her life is in danger," the hospital said.

Iranian President Ebrahim Raisi claimed Sunday that Iran had taught Israel a lesson and warned of a "heavier" response to "any new adventures against the interests of the Iranian nation." The Iranian envoy to the United Nations said Sunday that "the issue can be considered closed."

White House National Security Council spokesman John Kirby told ABC's "Good Morning America" Sunday that any response to Iran's attack is up to Israeli forces. But he stressed that President Joe Biden does not want the situation to escalate or have the U.S. drawn further into any conflict.

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 launched 170 unmanned aerial vehicles (UAVs), more than 120 ballistic missiles and more than 30 cruise missiles in the attack, according to Hagari.

Hagari said "99% of the threats launched towards Israeli territory were intercepted -- a very significant strategic achievement."

What is the Iron Dome and how does it work?

Like many modern air defense systems, an Iron Dome battery uses a sophisticated radar system to track inbound missiles that are then intercepted by Tamir missiles fired from multiple launchers attached to the radar system.

Each Iron Dome battery consists of three to four launchers that can each carry up to 20 Tamir interceptor missiles.

The system can bring down rockets fired from a range of 2 to 40 miles away.

The mobile air defense system first became operational in 2011 and since then has had a very high success rate in intercepting rockets targeting Israel.

The IDF has disclosed that in May 2023, when Islamic Jihad launched a barrage of rockets toward Israel, 95.6% of the Iron Dome interceptors launched by the system successfully destroyed incoming rockets.

The IDF's information highlights the reality that an interceptor missile is not fired at every rocket that makes it into Israeli territory. Instead, based on tracking data, the system fires interceptors only if an incoming rocket poses a threat to a populated area. If not deemed to pose a threat, then the incoming rocket will land in an unpopulated area.

The Iron Dome is typically located around cities or smaller populated areas that have been targeted in the past by incoming rockets.

ABC News' Luis Martinez contributed to this report.