Iran promised a harsh response and Israel said it was working to intercept about 100 drones launched towards Israeli territory in retaliation.

But around 8 a.m., Israeli media said an order to citizens to remain near protected areas had been lifted, suggesting that most or all the drones had been neutralized.

The price of crude oil leapt on fears of retaliatory attacks on a major oil producing region, but then eased back somewhat.

An Israeli security source said Israeli Mossad commandos had operated deep inside the Islamic Republic before the attack and the Israeli spy agency and military had led a series of covert operations against Iran's strategic missile array.

Israel also established an attack-drone base near Tehran, the source added. The military said it had carried out a large-scale strike against Iran's air defenses, destroying "dozens of radars and surface-to-air missile launchers".

Iranian media and witnesses reported explosions including at the main uranium enrichment facility at Natanz.

Iran's elite Revolutionary Guards Corps said its top commander, Hossein Salami, had been killed and state media reported the unit's headquarters in Tehran had been hit. Several children were killed in a strike on a residential area in the capital, they said.

"We are at a decisive moment in Israel's history," Israeli Prime Minister Benjamin Netanyahu said in a recorded video message.

"Moments ago, Israel launched Operation Rising Lion, a targeted military operation to roll back the Iranian threat to Israel's very survival. This operation will continue for as many days as it takes to remove this threat."

He warned Israelis that they might have to remain in shelter for extended periods.

At the same time, Israel has limited Iran's ability to retaliate by severely weakening its Middle East allies since the war in Gaza erupted in October 2023, assassinating top leaders of the Palestinian militant group Hamas and Lebanon's Hezbollah.

Some 200 Israeli fighter jets took part in the strikes, hitting more than 100 targets in Iran, military spokesman Brigadier General Effie Defrin said.

He told an online briefing Israel had been able to confirm that the chief of staff of the Iranian Armed Forces, the commander of the Revolutionary Guards and the commander of Iran’s Emergency Command had all been killed in the strikes.

Six Iranian nuclear scientists were killed, Iranian state media reported.

The International Atomic Energy Agency said there was no increase in radiation levels at the Natanz nuclear site, citing information provided by Iranian authorities.

Supreme Leader Ayatollah Ali Khamenei said in a statement that Israel had "unleashed its wicked and bloody" hand in a crime against Iran and that it would receive "a bitter fate for itself".

Regional airspace empties, flights canceled

Airlines quit the airspace over Israel, Iran, Iraq and Jordan after the Israeli strikes, Flightradar24 data showed, with carriers diverting or cancel flights.

Israeli airlines El Al, Israir and Arkia said they were moving their planes out of Israel and Tel Aviv's Ben Gurion Airport was shut.

Dubai-based Emirates cancelled flights to and from Iraq, Jordan, Lebanon and Iran as Iran closed its airspace.

The United States, which was due to hold the latest round of talks with Iran on restricting its nuclear program on Sunday, said it had had no part in the operation.

The National Iranian Oil Refining and Distribution Company said oil refining and storage facilities had not been damaged and continued to operate.

Israeli military Chief of Staff Eyal Zamir said tens of thousands of soldiers had been called up and "prepared across all borders".

"We are amidst a historic campaign unlike any other. This is a critical operation to prevent an existential threat, by an enemy who is intent on destroying us," he said.

US President Donald Trump said that Iran cannot have a nuclear bomb and that the United States was hoping to get back to the negotiating table, in an interview with Fox News after the start of the Israeli air strikes on Iran.

"We will see," Fox News reporter Jennifer Griffin quoted Trump as saying in a post on X.

US officials have repeatedly said that any new nuclear deal with Iran - to replace a 2015 accord between Tehran and six world powers from which Trump withdrew - must include a commitment to scrap enrichment, a potential pathway to developing nuclear bombs.

Nuclear talks with Iran due on Sunday

The Islamic Republic has repeatedly denied such intentions, saying it wants nuclear energy only for civilian purposes, and has publicly rejected Washington's demand to scrap enrichment as an attack on its national sovereignty.

The IAEA's Board of Governors on Thursday declared Iran in breach of its non-proliferation obligations for the first time in almost 20 years.

Iran said in a statement that Israel's "cowardly" attack showed why Iran had to insist on enrichment, nuclear technology and missile power.

The Israeli military said it had been forced to act by new intelligence information showing that Iran was "approaching the point of no return" in the development of a nuclear weapon.

But a source familiar with U.S. intelligence reports said there had been no recent change in the US assessment that Iran was not building a nuclear weapon and that Khamenei had not authorized a resumption of the nuclear weapons program that was shut in 2003.

Trump was convening a meeting the National Security Council on Friday morning, the White House said. He had said on Thursday that an Israeli strike on Iran "could very well happen" but reiterated his hopes for a peaceful resolution.

Iran's armed forces spokesperson said Israel and its chief ally the United States would pay a "heavy price" for the attack, accusing Washington of providing support for the operation.

While the US tried to distance itself from Israel's attack, an Israeli official told public broadcaster Kan that Israel had coordinated with Washington.

Secretary of State Marco Rubio said the US was not involved in the strikes and Tel Aviv had acted unilaterally for self-defense.

US and Iranian officials are scheduled to hold a sixth round of talks on Tehran's escalating uranium enrichment program in Oman on Sunday. A US official said those talks were still due to proceed.

The attacks triggered sharp falls in stock prices in Asian trade, led by a selloff in US futures. Israel's shekel slid nearly 2 percent.