Israel warned Saturday that "Tehran will burn" if Iran keeps targeting its civilians and boasted it now had control of the airspace from western Iran all the way to the capital.
"The Iranian dictator is turning the citizens of Iran into hostages and bringing about a reality in which they — especially the residents of Tehran — will pay a heavy price because of the criminal harm to Israeli civilians," said Defense Minister Israel Katz.
"If [Iranian Supreme Leader Ayatollah Ali] Khamenei continues to fire missiles toward the Israeli home front, Tehran will burn."
The Israeli military said its raids had cleared its path to the capital. "We have created aerial freedom of action from west Iran all the way to Tehran ... Tehran is no longer immune," said spokesman Brigadier General Effie Defrin.
The threat came as Israel and Iran exchanged fire a day after Israel unleashed an unprecedented aerial bombing campaign that Iran said hit its nuclear facilities, "martyred" top commanders, and killed dozens of civilians.
Iran has hit back with waves of drone and missile strikes, with a barrage of dozens lighting up the skies over Jerusalem and Tel Aviv overnight, killing three people and wounding dozens.
Following decades of enmity and conflict by proxy, it is the first time that Israel and Iran have traded fire with such intensity, with fears of a prolonged conflict engulfing the region.
Israel launched the aerial assault early Friday, only days before Iran and the United States had been due to hold a sixth round of talks on the Islamic Republic's nuclear program.
The operation — dubbed "Rising Lion" — struck Iran's Natanz uranium enrichment plant and assassinated Iran's highest-ranking military officer, Mohammad Bagheri, as well as the head of the powerful Revolutionary Guards, Hossein Salami, among other senior generals.
On Saturday, the Israeli military said it had Tehran in its sights after strikes on dozens of missile launchers and air defenses.
"The way to Iran has been paved," the military's chief of staff and air force chief were quoted as saying in a statement.
The military "is proceeding according to its operational plans, and [Israeli Air Force] fighter jets are set to resume striking targets in Tehran," it added.
Iran's U.N. ambassador said 78 people had been killed and 320 wounded in Friday's first wave of Israeli strikes.
Iranian media reported two Revolutionary Guards killed Saturday in an Israeli strike on a base in the country's center.
Iran called on its citizens to unite in the country's defense as Israeli Prime Minister Benjamin Netanyahu urged them to rise up.
A report in Iran's Mehr news agency said the IslamicRepublic had warned Britain, France, and the United States it could retaliate if they came to Israel's defense.
"Any country that participates in repelling Iranian attacks on Israel will be subject to Iranian forces targeting all regional bases of the complicit government," it said without citing any officials.
Overnight, air raid sirens and explosions rang out across Israel, with many residents holed up in bomb shelters.
The Israeli military said three people were killed and 76 injured in Israel since Iran began its attacks.
Israel said dozens of missiles — some intercepted — had been fired from Iran. AFP images of the city of Ramat Gan near Tel Aviv showed blown-out buildings, destroyed vehicles, and streets strewn with debris.
Iran's Revolutionary Guards said they had attacked dozens of targets in Israel. One Iranian missile wounded seven Israeli soldiers, the military said.
Firefighters had worked for hours to free people trapped in a Tel Aviv high-rise building on Friday.
Chen Gabizon, a resident, said he ran to an underground shelter after receiving an alert.
"After a few minutes, we just heard a very big explosion. Everything was shaking. Smoke, dust, everything was all over the place," he said.
Rescuers said 34 people were wounded in the Gush Dan area, including a woman who later died of her injuries, according to Israeli media reports.
Speaking to CNN, Israel's ambassador to the United States, Yechiel Leiter, said Iran had fired three salvos of ballistic missiles on Friday, some 150 in total.
"We expect that the Iranians, who have a considerable volume of ballistic missiles, somewhere in the neighbourhood of 2,000, will continue to fire them," Leiter said.
In Tehran, fire and heavy smoke billowed over Mehrabad airport on Saturday, an AFP journalist said, as Iranian media reported an explosion.
Blasts were heard across the capital as Iran activated its air defenses against the incoming fire.
Dozens of Iranians took to the streets to cheer their country's military response, with some waving national flags and chanting anti-Israel slogans.
The attacks prompted several countries in the region to temporarily ground air traffic; though on Saturday morning, Jordan, Lebanon, and Syria reopened their airspace.
Iran's airspace was closed until further notice, state media reported.
As fears mounted of wider conflict, U.N. chief Antonio Guterres called on both sides to cease fire.
"Enough escalation. Time to stop. Peace and diplomacy must prevail," he said on X late Friday.
Pope Leo XIV appealed for Israel and Iran to show "responsibility and reason."
Asked how long the war would last, Israel's ambassador to Paris, Joshua Zarka, said: "A small number of weeks." Netanyahu had said on Friday the strikes would "continue as many days as it takes."
The conflict has thrown into doubt Sunday's planned Iran-U.S. nuclear talks in the Gulf sultanate of Oman.
After Friday's first strikes, President Donald Trump urged Iran to "make a deal," adding the United States was "hoping to get back to the negotiating table."
Western governments have repeatedly accused Iran of seeking a nuclear weapon, an allegation it denies.
Iran said on Saturday it would be "meaningless" to attend the talks while it was under attack by Israel.