Israel said it carried out strikes across Iran on Monday, ignoring a public appeal from US President Donald Trump to avoid retaliation after Tehran launched a missile barrage a day earlier.
The attacks further strained a fragile truce reached on 8 April as the conflict entered its 100th day. They also complicated ongoing US efforts to secure an agreement with Tehran aimed at ending the war.
Iranian state television reported explosions in three cities, including Tehran. The Israeli military said it had targeted sites in western and central Iran.
The strikes were a direct response to Iran's launch of 11 missiles towards Israel on Sunday. Israeli authorities said all the missiles were intercepted and no casualties were reported.
Before the Israeli operation, Trump had attempted to dissuade Prime Minister Benjamin Netanyahu from retaliating after Israel accused Iran of making a "grave mistake".
"I am going to call Bibi right now and tell him not to retaliate," Trump told Axios journalist Barak Ravid in a phone interview, using Netanyahu's nickname.
"Israel had its strike and Iran had its strike. We don't need another one," he said.
Ravid later reported that a US official confirmed Trump had spoken with Netanyahu, although neither the White House nor the president issued any immediate public comment.
Britain's Foreign Secretary Yvette Cooper also urged both sides to show restraint.
"The resumption of conflict between Iran and Israel is in no one's interest," she wrote on X, calling for a diplomatic solution.
Tehran has repeatedly insisted that any agreement to permanently end the war must also address the parallel conflict in Lebanon, where Israel is conducting military operations against the Iran-backed Hezbollah movement. Iranian officials have warned that any new attack on Beirut would trigger a "full-scale resumption" of hostilities.
Iranian foreign ministry spokesman Ali Safari told Al-Mayadeen television that Tehran's missile strikes came after weeks of restraint in response to what he described as Israeli aggression, according to local media reports.
Iran's Revolutionary Guards described Sunday's attack on Israel as a "warning" following an Israeli strike on Beirut's southern suburbs earlier in the day. The force warned that any further attacks would provoke a broader response.
Regional tensions increased further on Monday when Iran launched strikes against what it described as the headquarters of "terrorist groups" in Iraq's Kurdistan region. Tehran accuses armed Kurdish groups of acting on behalf of Western or Israeli interests.
The Israeli military also said it was attempting to intercept a missile launched from Yemen, where Houthi rebels have repeatedly targeted Israel during the conflict.
Earlier on Sunday, Netanyahu's office said Israeli forces had struck a militant command centre in Beirut's Dahiyeh district in response to Hezbollah fire towards Israeli territory.
Lebanon's health ministry said the raid killed two people and wounded 20 others.
Israel had previously warned it would target the area if Hezbollah attacked northern Israel. The group later confirmed launching missiles and drones at two Israeli military barracks.
Mohammad Bagher Ghalibaf, Iran's parliament speaker and chief negotiator in talks with Washington, accused the United States of giving a "green light" to the Beirut strike. He said US and Israeli assets were now "legitimate targets".
The head of Iran's military central command said Israel had "crossed all red lines" with the attack and demanded an end to its campaign in Lebanon.
"Tonight's operation (against Israel) was a warning," the Revolutionary Guards said. "If such aggressions are repeated, the responses will be broader and will cover all US-Zionist targets in the region."
Shortly after the exchange of attacks, Iran closed its western airspace. Iraq and neighbouring Syria followed with similar restrictions. Tehran also suspended all incoming flights to its main international airport, according to local media.
The escalation pushed oil prices higher as hopes faded for the near-term reopening of the Strait of Hormuz, a vital route for global oil and gas shipments that Iran has effectively closed.
Inside Iran, many residents said weeks of uncertainty were taking a heavy toll.
"I really have gone numb," Elaheh, a 32-year-old fitness trainer from Ahvaz, told AFP.
"Daily life? It's a joke. Everything is horrible. We only try to survive," she said, citing rising prices and economic hardship.
Diplomatic efforts continued over the weekend. Pakistan's Interior Minister Mohsin Naqvi arrived in Tehran on Saturday carrying what Iranian state television described as a "special letter" from Pakistan's army chief to Iran's supreme leader, along with a message from the prime minister.
Pakistan's military chief, Syed Asim Munir, has played a central role in mediation efforts between Iran and the United States following an initial round of direct negotiations in Islamabad.
Mohsen Rezaei, a military adviser to Iranian Supreme Leader Ayatollah Mojtaba Khamenei, told CNN that negotiations with Washington were "at a deadlock, and Trump must break this deadlock". He also called for the release of around $24 billion in frozen Iranian assets.
Trump, however, said he would not release Iranian assets before an initial agreement was reached.
"If they behave, if they do a good job, we start talking," he told NBC on Sunday.
