Scores of Israeli jets completed three waves of strikes before dawn against missile factories and other sites near Tehran and in western Iran, Israel's military said.
It was retaliation for Iran's Oct. 1 attack on Israel with about 200 ballistic missiles, and Israel warned its heavily armed arch-foe not to hit backafter the latest strike.
Iran condemned the Israeli raid and its foreign ministry said Iran was "entitled and obligated" to defend itself. But it added that it "recognises its responsibilities towards regional peace and security," a more conciliatory statement than after previous bouts of escalation.
Iran's military said the Israeli warplanes used "very light warheads" to target border radar systems in the provinces of Ilam, Khuzestan and around Tehran.
"Enemy planes were prevented from entering the country's airspace... and the attack caused limited damage," Iran's military joint staff said in a statement.
David Albright, a former U.N. nuclear weapons inspector, said low resolution commercial satellite imagery appeared to show that one Israeli strike hit the sprawling Parchin military complex near Tehran, damaging three buildings, including two where solid fuel was mixed for ballistic missile engines.
Tensions between Iran and Israel have grown rapidly since the Oct. 7, 2023 attack on Israel by Iran-backed Hamas, raising fears of a wider regional conflict that could drag in global powers and imperil world energy supplies.
Worsening conflict in Lebanon, where Israel is waging an intense campaign against Iran's main regional ally Hezbollah to stop it firing rockets into northern Israel, has raised the temperature still further.
The United States, which had pressed Israel to avoid targeting sensitive Iranian energy and nuclear sites, joined other countries in calling for a halt to the cycle of confrontation between Israel and Iran.
Israeli Prime Minister Benjamin Netanyahu said on Saturday that Israel had chosen the targets in Iran based on its national interests, not according to what was dictated by the United States.
Biden said the strikes appeared to have only hit military targets and added that he hoped they were "the end".
Vice President Kamala Harris, who hopes to succeed Biden by winning the Nov. 5 US presidential election, said it was "the strong perspective of the United States that there must be de-escalation."
Two regional officials briefed by Iran told Reuters that several high-level meetings were held in Tehran to determine the scope of Iran's response. One official said the damage was "very minimal" but added that several Revolutionary Guards bases in and around Tehran were also hit.
Iranian news sites aired footage of passengers at Tehran's Mehrabad Airport, seemingly meant to show there was little impact.
Israel's military, signalling it did not expect an immediate Iranian response, said there was no change to public safety restrictions across the country.
'MESSAGE TO IRAN'
Beni Sabti, an Iran expert at Tel Aviv's Institute for National Security Studies, said the Israeli strike had appeared designed to give Tehran an opportunity to avoid further escalation.
"We see that Israel wants to close this event, to pass this message to Iran that it is closed and we don't want to escalate it," he said.
Videos carried by Iranian media showed air defences continuously firing at apparently incoming projectiles in central Tehran, without saying which sites were coming under attack.
Israel's military said its jets had struck missile manufacturing facilities and surface-to-air missile arrays, and safely returned home.
"If the regime in Iran were to make the mistake of beginning a new round of escalation, we will be obligated to respond," the military said.
Israel notified the US before striking, but Washington was not involved in the operation, a US official told Reuters. Targets did not include energy infrastructure or Iran's nuclear facilities, a US official said.
In the days after Iran's strikes on Israel this month, Biden had warned that Washington, Israel's main backer and supplier of arms, would not support a retaliatory strike on Tehran's nuclear sites and had said Israel should consider alternatives to attacking Iran's oil fields.
Arab states situated between Israel and Iran have been particularly worried that use of their airspace could prompt retaliation against them.
Jordanian television quoted a source in the country's armed forces as saying no military planes had been allowed through its airspace. A Saudi official also said that Saudi airspace had not been used for the strike.
A regional intelligence source said Israeli jets had flown across southern Syria, emitting sonic booms near the Jordanian border, and then across Iraq.
Saudi Arabia, which has mended fences with Iran after years of regional rivalry, and had been edging towards better ties with Israel before the war in Gaza, condemned the attack as a violation of Iranian sovereignty and international law.
LEBANON CONFLICT
Israel's military eased some safety restrictions for residents in areas of northern Israel late on Saturday, a possible indication that it does not expect any immediate large-scale attack from Iran or its proxies in the region.
The decision followed a "situational assessment", it said in a statement.
Still, Lebanon's Hezbollah warned residents of more than two dozen towns in northern Israel to immediately evacuate, saying they had become legitimate targets because it said Israeli troops were stationed there.
Israel meanwhile said it had struck Hezbollah facilities in Beirut's southern Dahiyeh suburb including a weapons-making site and an intelligence headquarters.
The conflict in Lebanon, which has greatly intensified in recent weeks, has also led to strikes on sites linked to Iran and Hezbollah in Syria.
Israel launched airstrikes against some military sites in central and southern Syria early on Saturday, Syrian state news agency SANA reported. Israel has not confirmed striking Syria.
Efforts to secure a ceasefire and hostage-release deal in Gaza, which could help cool the wider conflict, are expected to resume in Doha when negotiators fly there on Sunday.
