Iran has indicated it has no plans for retaliation as it played down a strike by Israel after Tehran’s unprecedented missile-and-drone assault on the country.
Troops fired air defences from a major military airbase and a nuclear site near the central city of Isfahan, reportedly hitting three drones.
There were no reports of damage or casualties.
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Israel has declined to comment, but a US source familiar with the situation told NBC News it was behind the strike.
The US told a meeting of G7 ministers on Friday it had been “informed at the last minute” by Israel about the attack, which coincided with the birthday of Iran’s supreme leader, Ayatollah Ali Khamenei.
Meanwhile, Iran has said it has no plans to respond and sought to downplay the operation.
Notably, a senior official said the country was looking at it as an “infiltration” rather than an “external attack”.
Iran’s President Ebrahim Raisi had previously warned Tehran would deliver a “severe response” to any hostile action.
The limited scale of the attack and Iran’s low-key response suggested frantic diplomatic efforts to avert an all-out war between the long-standing enemies had been successful.
Fears of a deeper Middle East conflict had been sparked after Iran’s weekend assault, which was largely thwarted by Israel and its allies.
This followed an airstrike on Iran’s embassy in the Syrian capital, Damascus, blamed on Israel, which killed several Iranian officers including a top general.
Analysis:
Targeted strike is a message – and Iran’s response is telling
The heightened tensions come against the backdrop of Israel’s ongoing war against Iranian-backed Hamas in Gaza, launched after the deadly incursion by the militant group on 7 October.
The US and other countries, including the UK, had been urging Israel not to take action that could escalate hostilities.
Speaking at the meeting of G7 foreign ministers on the southern Italian island of Capri, US secretary of state Antony Blinken repeatedly refused to be drawn on the attack on Iran.
He said: “I’m not going to speak on that except to say that the United States has not been involved in any offensive operations.”
Mr Blinken went on: “All I can say is that for our part, and for the entire G7, our focus has been on de-escalation, on avoiding a larger conflict.”
In a sign of the pressure within Israel’s hardline government for a tougher response, Itamar Ben Gvir, the far-right national security minister, tweeted a single word after Friday’s strike: “Feeble.”
Within Iran, news reports on Friday’s incident made no mention of Israel, and commentators on state TV were dismissive about the scale of the attack.
The airbase in Isfahan has long been home to Iran’s fleet of American-made F-14 Tomcat fighter jets, bought before the 1979 Islamic Revolution.
Isfahan also hosts the biggest nuclear research establishment in the country.
Although Tehran says its nuclear work is peaceful, the West believes the regime aims to build a weapon.
The UN’s nuclear watchdog, the International Atomic Energy Agency, said there was no damage to the nuclear facility but said it was monitoring the situation “very closely” and called for “extreme restraint”.
Iran shut its airports in Tehran, Shiraz and Isfahan and also closed the western portion of its airspace for several hours after the strike.
Around the same time, Israeli warplanes also struck a military radar in southern Syria.
Meanwhile, G7 foreign ministers have warned of fresh sanctions against Iran over its attack on Israel.