Iran's attack on Israel largely intercepted

• Iran's attack is in response to an April 1 Israeli airstrike in Syria that killed two Iranian generals inside an Iranian consulate building.
• In a statement carried by Iran’s state-run IRNA news agency, the country’s paramilitary Revolutionary Guard acknowledged Saturday launching "dozens of drones and missiles towards the occupied territories and positions of the Zionist regime."
• The attack marked the first time Iran had ever launched a full-scale military assault on Israel.
• The White House said it would provide unspecified support for Israel’s defense against the ongoing attack.
• Israel’s war on Hamas in the Gaza Strip has inflamed decade-old tensions in the Middle East, and any new attack threatens to escalate that conflict into a wider regional war.

12:30 a.m. ET - Israel says 99% of more than 300 Iranian drones, missiles were intercepted

An Israeli military spokesman said Sunday the launches numbered more than 300, but 99% of them were intercepted. 

Rear Adm. Daniel Hagari said Iran fired 170 drones, more than 30 cruise missiles and more than 120 ballistic missiles. Several ballistic missiles reached Israeli territory, causing minor damage to an air base.

9:07 p.m. ET - Israel says most Iranian drones intercepted 

Israeli military spokesperson Rear Admiral Daniel Hagari reported that Iran launched numerous drones, cruise missiles, and ballistic missiles, the majority of which were intercepted before reaching Israeli territory. 

Over 10 cruise missiles were intercepted outside Israel's airspace by warplanes.

Despite interceptions, a few missiles landed in Israel, resulting in critical injuries to a 10-year-old girl in a town in southern Israel, while another missile caused minor damage to an army base without injuring anyone, as confirmed by Hagari.

7:43 p.m. ET - UK sending jets, fuel tankers to Middle East

UK Defense Secretary Grant Shapps announced the dispatch of more Royal Air Force jets and air refueling tankers to the Middle East, enhancing Britain's ongoing mission against the Islamic State Group in Iraq and Syria. 

He said the jets "will intercept airborne attacks within range of our existing missions," but did not confirm whether RAF jets had already shot down any Iranian drones.

7:28 p.m. ET - President Biden reaffirms support for Israel

Shortly following the initial impact of the Iranian drones on Jerusalem, President Biden took to X, formerly known as Twitter, to reiterate America's unwavering dedication to supporting Israel.

"I just met with my national security team for an update on Iran’s attacks against Israel. Our commitment to Israel’s security against threats from Iran and its proxies is ironclad," Biden wrote. 

7:02 p.m. ET - Reports of US shooting down drones

U.S. forces have downed some Iran-launched attack drones flying toward Israel, the Associated Press was reporting, according to sources. 

Fox News was also reporting that the U.S. military was continuing to shoot down Iranian drones headed toward Israel.

"U.S. forces in the region continue to shoot down Iranian-launched drones targeting Israel. Our forces remain postured to provide additional defensive support and to protect U.S. forces operating in the region," a U.S. military official said, Fox News reported.

6:48 p.m. ET - Sirens, first booms heard in Jerusalem

Air raid sirens have sounded in Jerusalem as explosions were heard in the skies. 

At least six booms sounded as Iranian drones arrived early Sunday. 

There is no immediate word from authorities on whether the explosions are an incoming attack or the sound of interceptions.

6:40 p.m. ET - Israel orders residents in some areas to move close to protected spaces 

The Israeli army has ordered residents of the Golan Heights in the north and Nevatim, Dimona and Eilat in the south to stay close to a protected space — such as a shelter, stairwell or inner room — until further notice.

Residents must be able to reach the protected spaces as soon as air raid sirens are activated, the statement said.

"We ask the public to follow the instructions of the Home Front Command regarding the situation and wait for additional instructions," the statement said.

5:55 p.m. ET - Iran says it fired ballistic missiles

Iran’s state-run IRNA news agency says Tehran has fired ballistic missiles at targets inside of Israel. The announcement came shortly after Iran said it fired dozens of bomb-carrying drones.

Slow-moving Shahed-136 drones have been seen in the skies over Iran. However, those are more easily shot down.

Israel has missile defense systems capable of targeting ballistic missiles. However, in a massive attack involving multiple drones and missiles like the campaign launched late Saturday by Iran, the likelihood of a strike making it through is higher.

5:53 p.m ET - Israel’s military says over 100 drones were fired

Israel's military reported the launch of over 100 drones, affirming its readiness to counter the attack with prepared air defenses and a swift response. Concurrently, the U.S. maintains a substantial troop presence in the region, standing ready to support as needed.

4:38 p.m ET - U.S. pledges support

The White House said the U.S. will 'support' Israel's defense against airborne attack from Iran.

U.S. National Security Council spokesperson Adrienne Watsons said in a Saturday statement that "Iran has begun an airborne attack against Israel. President Biden is being regularly updated on the situation by his national security team and will meet with them this afternoon at the White House."

4:30 p.m. ET - Israeli airspace closed 

Israel aviation authorities will close Israeli airspace to all flights ahead of the impending Iranian drone strike.

4:10 p.m. ET - Israeli military says Iran launched drones 

Iran has deployed multiple drones toward Israel, following Israel's bombing that resulted in the deaths of several Iranian officials earlier this month, the IDF confirmed on Saturday.

Rear Adm. Daniel Hagari, the IDF's spokesperson, stated on Saturday evening that it would take several hours for the aircraft to reach their destination, reaffirming Israel's readiness for any potential threat.

Overnight - Iran seizes Israeli-linked cargo ship

Iran's Revolutionary Guard seized an Israeli-linked container ship near the Strait of Hormuz on Saturday.

Following that news, President Biden cut short a weekend stay at his Delaware beach house and returned to the White House to meet with his national security team and monitor the situation in the Middle East.

What are Israel's defense capabilities? 

Israel possesses multiple layers of air defense capable of intercepting various threats, ranging from long-range missiles to UAVs and short-range rockets. Hagari emphasized that while Israel boasts an "excellent air defense system," it is not infallible and urged the public to heed safety announcements.

Approximately 169,500 active-duty personnel and roughly 465,000 Israelis serve in reserve units, according to a report from Axios. Following the Hamas attack on October 7th, over 300,000 reservists have been mobilized. The IDF's annual budget, totaling around $23.6 billion as of 2023, exceeds the combined military spending of Egypt, Iran, Lebanon, and Jordan.

Israel is also believed to have dozens of nuclear warheads in its arsenal, though it has neither confirmed nor denied its nuclear capability. 

Why Iran is attacking Israel

Israel's ongoing confrontation with Hamas in the Gaza Strip has sparked renewed tensions across the Middle East, adding fuel to longstanding animosities. 

Israel has been on high alert following an airstrike last week that resulted in the deaths of two Iranian generals in Syria. Iran has accused Israel of orchestrating the attack and has pledged retaliation. Israel has refrained from commenting on the incident.

Earlier on Saturday, the Israeli military announced the cancelation of school and imposed restrictions on public gatherings, limiting them to a maximum of 1,000 people as a safety measure.

President Joe Biden told reporters on Friday afternoon that he expected an Iranian strike on Israel to occur "sooner than later." 

When Biden was asked for a message to Iran, Biden bluntly and simply responded, "Don’t."

Biden also acknowledged that he needed to be careful not to reveal classified information being collected by intelligence and military officials as they braced for an attack.

READ MORE: Why Iran wants to attack Israel: The history of the conflict explained

John F. Kirby, a spokesman for the National Security Council, also said Friday that the administration was taking the threat of an attack seriously.

"We are certainly mindful of a very public — and what we consider to be a very credible — threat made by Iran in terms of potential attacks on Israel," he said. "We are in constant communication with our Israeli counterparts about making sure that they can defend themselves against those kinds of attacks."

RELATED: U.S. moves "additional assets" to Middle East amid threat of Iranian strike on Israel

The U.S. also said it was moving "additional assets" to the Middle East region "to bolster regional deterrence efforts and increase force protection for U.S. forces," a U.S. defense official told Fox News.

In addition, the State Department issued new travel advisories for Israel on Thursday, restricting U.S. government employees and their families from traveling outside major cities. The department warned, "Terrorist groups, lone-actor terrorists and other violent extremists continue plotting possible attacks in Israel, the West Bank, and Gaza. Terrorists and violent extremists may attack with little or no warning." 

Attack on Iranian consulate

Tehran has continued to threaten a response against Israel for the attack on an Iranian consulate in Damascus that killed seven Islamic Revolutionary Guard Corps (IRGC) members, including two generals. 

Hezbollah leadership over the weekend at the annual Quds Day commemoration in Iran also touted their readiness and willingness to launch retaliation against Israel for the attack. 

Israeli military officials suggested on Thursday that further conflict could arise if Iran retaliated for the deadly airstrike.

This story was reported from Los Angeles. FOX News and the Associated Press contributed.