This article has been updated from the bulldog edition

JERUSALEM — The launching of more than 100 drones and ballistic missiles at Israel from Iran is an unprecedented revenge mission that pushes 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. America, with its large troop presence in the region, said it would provide unspecified support to Israel.

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. 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.

The Israel Defense Forces spokesman, Rear Admiral Daniel Hagari, speaking Saturday evening, said it would take several hours for the aircraft from the Islamic Republic to arrive. 

Israel has been on heightened alert since an airstrike last week killed two Iranian generals in Syria. Iran accused Israel of being behind the attack and vowed revenge. Israel has not commented on that strike, which hit a building next to the Iranian consulate at Damascus.

An American official briefed on the attack said Iran had launched “dozens” of drones. The official could not publicly discuss details of the attack and spoke to the Associated Press on condition of anonymity.

Earlier Saturday, the Israeli military said it was canceling school and limiting public gatherings to no more than 1,000 people as a safety precaution.

Briefing reporters, Admiral Hagari said Israel is “prepared and ready” with defensive and offensive actions. He also said there was “tight” cooperation with America and other partners in the region.

The head of the United States Central Command, General Erik Kurilla, has been in Israel in recent days to coordinate with Israel about how best to handle the Iranian threat. 

The Jewish state has a number of layers of air defense capable of intercepting everything from long-range missiles to unmanned aerial vehicles and short-range rockets.

Admiral Hagari said Israel has an “excellent air defense system” but stressed it is not 100 percent effective and urged the public to listen to safety announcements.

President Biden cut short a weekend stay at his Delaware beach house and was returning to the White House on Saturday to meet with his national security team and monitor the situation in the Middle East as Iran launched an attack against Israel.

Mr. Biden on Friday said the United States was “devoted” to defending Israel and that “Iran will not succeed.” Asked by reporters what his message was for Iran, the president’s only reply was: “Don’t.”

Amid concerns about the increased tensions, Lufthansa Group on Saturday extended its suspension of flights between Frankfurt and Tehran through Thursday and said its planes would avoid Iranian airspace.

The German carrier also said that, until at least Tuesday, flights to and from Amman will be operated as “day flights” so crews won’t spend a night at the Jordanian capital.

Dutch airline KLM said it will no longer fly over Iran or Israel but will continue flights to and from Tel Aviv.