Iran says it has launched ballistic missiles as part of its attack targeting Israel.

The state-run IRNA news agency quoted an anonymous official saying ballistic missiles were part of the attack.

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

A ballistic missile moves on an arch trajectory, heading up into space before gravity brings the weapon down at a speed several times faster than the speed of sound.

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.

Iran launched dozens of drones toward Israel late Saturday, Israeli and Iranian officials confirmed, on an unprecedented revenge mission that pushed the Middle East ever closer to a regionwide war.

Israel's military said over 100 drones had been fired but that its air defenses were prepared for the attack and it was ready to respond. The U.S., with its large troop presence in the region, said it would provide unspecified support to Israel.

“We are monitoring the threat,” the Israeli military's spokesman, Rear Adm. Daniel Hagari, announced in a nationwide television address, saying it would take several hours for the drones to reach Israel. The Israeli military said it could not confirm if it had intercepted any drones or what their targets were.

The attack marked the first time Iran had ever launched a full-scale military assault on Israel, despite decades of enmity dating back to the country's 1979 Islamic Revolution.

Iran had vowed revenge since an April 1 airstrike in Syria killed two Iranian generals inside an Iranian consular building. Iran accused Israel of being behind the attack. Israel hasn't commented on it.

Israel and Iran have been on a collision course throughout Israel's six-month war against Hamas militants in the Gaza Strip. The war erupted after Hamas and Islamic Jihad, two militant groups backed by Iran, carried out a devastating cross-border attack on Oct. 7 that killed 1,200 people in Israel and kidnapped 250 others. An Israeli offensive in Gaza has caused widespread devastation and killed over 33,000 people, according to local health officials.

Almost immediately after the war erupted, Hezbollah, an Iranian-backed militant group in Lebanon, began attacking Israel's northern border. The two sides have been involved in daily exchanges of fire, while Iranian-backed groups in Iraq, Syria and Yemen have launched rockets and missiles toward Israel.

In a statement carried late Saturday by Iran's state-run IRNA news agency, the country's paramilitary Revolutionary Guard acknowledged launching “dozens of drones and missiles towards the occupied territories and positions of the Zionist regime.” The statement did not elaborate.

Online videos shared by state television purported to show delta-wing-style drones resembling the Iranian Shahed-136 drones long used by Russia in its war on Ukraine. The drones are bomb-carrying and slow-flying. Ukraine has successfully used both surface-to-air missiles and ground fire to target the drones.

Iran has a vast arsenal of drones and missiles. Tehran's choice of the Shahed-136 drones give Israel and its allies hours to shoot them down. It does not appear Iran used any of its ballistic missiles in the attack, which would pose a greater risk to Israel.

Israel has a multilayered air-defense network that includes systems capable of intercepting a variety of threats including long-range missiles, cruise missiles, drones and short-range rockets.

Hagari, the army spokesman, said Israel was “prepared and ready” with both defensive and offensive responses. But he cautioned that the air defenses are not 100% effective and urged the public to heed safety instructions.

The army's Home Front Command canceled school on Sunday and limited public gatherings to no more than 1,000 people. Israel closed its airspace and canceled all flights.

Earlier Saturday, Prime Minister Benjamin Netanyahu warned: “Whoever harms us, we will harm them.”

In Washington, President Joe Biden cut short a weekend trip to his beach house in Delaware to return to the White House. He was set to convene a principals meeting of the National Security Council on Saturday to discuss the unfolding attack, the White House said.

“The United States will stand with the people of Israel and support their defense against these threats from Iran,” National Security Council spokesperson Adrienne Watson said in a statement.

Gen. Erik Kurilla, the head of the U.S. Military's Central Command, was in Israel over the weekend consulting with Israeli defense officials about the Iranian threat. The Central Command oversees U.S. Forces in the Middle East, while Israel has a formidable arsenal that includes long-range missiles and F-35 stealth warplanes.

For days, Iranian officials including Supreme Leader Ayatollah Ali Khamenei had threatened to “slap” Israel for its Syria strike.

In Iran's capital, Tehran, witnesses saw long lines at gas stations early Sunday as people appeared worried about what may come next. Dozens of hard-liners demonstrated in support of the attack at Palestine Square.

Lebanon's state-run National News Agency reported heavy Israeli airstrikes and shelling on multiple locations in south Lebanon following Iran's launch of drones.

Flight-tracking data late Saturday showed the airspace over Jordan empty, while few flights continued on their north-south routes over Iraq. A sole Middle East Airlines flight from Dubai to Beirut remained airborne over Syria. Lebanon was closing its airspace.

Earlier Saturday, commandos from Iran's paramilitary Revolutionary Guard rappelled from a helicopter onto an Israeli-affiliated container ship near the Strait of Hormuz and seized the vessel.

Iran's state-run IRNA said a special forces unit of the Guard's navy carried out the attack on the Portuguese-flagged MSC Aries, a container ship associated with London-based Zodiac Maritime.

Zodiac Maritime is part of Israeli billionaire Eyal Ofer's Zodiac Group. Zodiac declined to comment and referred questions to MSC. Geneva-based MSC acknowledged the seizure and said 25 crew members were on the ship.

“We are working closely with the relevant authorities to ensure their well-being, and safe return of the vessel,” MSC said.

Watson, the White House spokesperson, said the crew was made up of Indian, Filipino, Pakistani, Russian and Estonian nationals and urged Iran to release them and the vessel.

IRNA said the Guard would take the vessel into Iranian territorial waters.

A Middle East defense official, who spoke on condition of anonymity to discuss intelligence matters, provided video of the attack to The Associated Press in which Iranian commandos are seen rappelling onto a stack of containers on the vessel's deck.

The video corresponded with known details of the MSC Aries. The commandos rappelled from what appeared to be a Soviet-era Mil Mi-17 helicopter, which both the Guard and the Iranian-backed Houthis in Yemen have used before to raid ships.