Israel launched an attack on Iran's capital early Friday, with explosions reported across Tehran.
According to Israeli officials, the strikes targeted key nuclear and military facilities.
The Israeli attack follows escalating tensions over Iran's rapidly advancing nuclear program.
Strikes on Iran over nuclear program that poses an 'existential threat,' says IDF
The Israel Defense Forces (IDF) has released a video statement on X, saying "for years, the Iranian regime has called for the destruction of the State of Israel, planning and advancing concrete military plans to do so."
"Over the past few months, intelligence has shown that Iran is closer than ever to obtaining a nuclear weapon," the statement, made by IDF spokesperson Effie Defrin, said.
"This morning, the IDF began preemptive and precise strikes, targeting the Iranian nuclear program in order to prevent the Iranian regime's ability to build a nuclear bomb in the immediate time frame."
"We are operating against an imminent and existential threat," the IDF statement continued. "We cannot allow the Iranian regime to obtain a nuclear weapon that would be a danger to Israel and the entire world."
US not involved in Israeli strikes: Rubio
US Secretary of State Marco Rubio said on Thursday that the United States was not involved in Israel's strikes against Iran.
He also issued a warning to Tehran, urging it not to retaliate by targeting US personnel or assets in the region.
"Tonight, Israel took unilateral action against Iran. We are not involved in strikes against Iran," Rubio said in a statement.
"Let me be clear: Iran should not target US interests or personnel," he added.
This came after President Donald Trump warned of a possible "massive conflict" in the region and US personnel were being moved out of the Middle East due to heightened regional tensions.
"Well, they are being moved out because it could be a dangerous place," Trump told reporters in Washington on Wednesday.
Flights suspended from Tehran's main international airport
Iran has suspended flights at Imam Khomeini International Airport, the country's main airport, state TV said, citing the airport's public relations department.
This comes after Israel launched strikes against Iran's nuclear program, including several in the capital Tehran.
The commander of Iran's paramilitary Revolutionary Guards has been killed, according to media reports on Friday.
Iranian state television said Hossein Salami is "feared dead."
The Revolutionary Guards are one of the most powerful and feared organizations in Iran.
Hossein Salami was on the sanctions lists of several countries, including Australia, Switzerland, the European Union and the United Kingdom, according to the open-source sanctions data base, Open Sanctions.
Iran's state broadcaster added that one other top Guard official, as well as two nuclear scientists, were also believed to have been killed.
On Thursday, Hossein Salami had warned that Iran's retaliation to any Israeli aggression would be "more forceful and destructive" than in the past.
US calls National Security Council meeting, Trump to attend
US President Donald Trump will attend a National Security Council meeting on Friday morning, the White House said.
The meeting of top security chiefs from across the US government would be held at 11:00 a.m. (1500 GMT/UTC).
The announcement of the meeting comes after Israel launched a wave of strikes against Iran, prompting fears of a regional war.
Iraq, Iran and Israel close airspace
Iraq closed its airspace entirely on Friday following the Israeli strikes on Iran.
The ministry of transportation announced a "temporary closure of Iraqi airspace" and complete suspension of air traffic.
Meanwhile, Iran has now also closed its airspace after earlier shutting Imam Khomeini International Airport, the country's main airport.
Israel's airspace is also closed for takeoffs and landings until further notice, Israeli media has reported, citing the country's Transportation Ministry.
Top Iranian military commander killed in Israeli strikes: state TV
Iran's chief of staff of the armed forces was killed in Israeli airstrikes on Friday, according to Iranian state television.
"Major General Mohammad Bagheri, chief of staff of the armed forces, was martyred," the state broadcaster announced.
Earlier reports said the commander of Iran's paramilitary Revolutionary Guards Hossein Salami was also "feared dead," with Iran vowing a response to his killing.
The Israeli attacks reportedly targeted multiple cities, including the capital, Tehran, and marks a significant escalation in the growing conflict between Israel and Iran.
IAEA says Natanz nuclear facility targeted, no radiation leaks reported
The International Atomic Energy Agency (IAEA) confirmed on Friday that Iran's Natanz nuclear facility was among the targets in recent Israeli strikes, but said no radiation leaks have been detected.
The IAEA quoted Director General Rafael Grossi on X saying Iranian authorities had reported that the Bushehr Nuclear Power Plant had not been hit, and that radiation levels at Natanz remained normal.
"The IAEA is closely monitoring the deeply concerning situation in Iran," Grossi said. "The Agency is in contact with Iranian authorities regarding radiation levels. We are also in contact with our inspectors in the country."
The statement comes amid heightened tensions following a wave of Israeli strikes across Iran, which targeted military and nuclear-related sites.
Israel braces for Iranian drone attack
Following the Israeli army's announcement that 100 drones have been launched from Iran in Israel's direction, the Israeli public are being told to stay close to so-called "safe spaces," meaning either a shelter based inside private apartments or houses, or public shelters.
Israeli media estimate that the drones are expected to reach Israeli airspace within seven hours from their launch in Iran.
The Israeli military said that once a siren goes off, civilians need to stay inside shelters until further notice, unlike in previous cases, such as the rockets launched in Israel's direction from Gaza, Yemen or Lebanon, in which Israelis were only told to stay in shelters for 10 minutes.
"We are prepared for a significant threat, one that's different in its intensity," the IDF's Home Front Command said on its website in Hebrew.
"For that reason, the next few hours need to be planned so that you'll be able to reach a shelter as quickly as possible once sirens go off."
6 Iranian nuclear scientists killed in Israeli strikes — reports
At least six Iranian nuclear scientists were killed in Israel's attack on Iran on Friday morning, according to local media.
The Iranian state news agency Tasnim named the "martyred" scientists as "Abdolhamid Minouchehr, Ahmadreza Zolfaghari, Amirhossein Feqhi, Motalleblizadeh, Mohammad Mehdi Tehranchi and Fereydoun Abbasi."
Tehranchi was the president of the Islamic Azad University of Iran and Abbasi was a former head of the Atomic Energy Organization of Iran, according to AFP.
Israel has said its strikes explicitly targeted Iranian nuclear sites in order to prevent Tehran from acquiring a nuclear weapon, which it claims would represent an existential threat.
Iranian drones intercepted outside Israel
The Israeli military said it has begun to intercept Iranian drones beyond the borders of Israel.
An Israeli official told The Associated Press and AFP news agencies that the first interceptions had taken place "outside of Israeli territory."
Israeli broadcaster KAN reported that Iranian UAVs (unmanned aerial vehicles) had been intercepted over Syria.
According to the Israel Defense Forces (IDF), Iran has launched over 100 drones toward Israel in retaliation for large-scale Israeli strikes on the Islamic Republic overnight.
Iran's Supreme Leader Ayatollah Ali Khamenei has been quoted as saying that Israel must expect "severe punishment."