Israel carried out air and missile strikes against Iran in the early hours of Friday local time, setting the stage for a major escalation in the world's largest oil producing region.
Israel said it struck military targets and infrastructure associated with Iran's nuclear programme across the country. It claimed the attack was carried out in self-defense, as "Iran is closer than ever to obtaining a nuclear weapon."
Iranian state media reported a first wave of strikes over the capital city, Tehran, at around 03:20 local time (23:50 GMT). Images and videos published by the state broadcaster showed residential towers that had been struck in the attack, causing numerous casualties.
There were reports soon after of fire and smoke at the general command headquarters of the Islamic Revolutionary Guards Corps (IRGC) in the east of the capital, and strikes elsewhere in the country, among them key sites like the Shahid Ahmadi Roshan nuclear site in Natanz, around 200km south of the capital.
Iran's civil aviation authority announced within two hours of the initial strikes that all flights had been grounded at all of the country's airports, and that the airspace over Iran will be closed "until further notice."
Following the strikes on the IRGC headquarters, Iranian state media was quick to dismiss reports suggesting casualties among the country's top military officers. But news has emerged on the death of key individuals, including the IRGC's commander-in-chief Hossein Salami and Iran's army chief, Mohammad Bagheri.
Iran's Supreme Leader Ayatollah Ali Khamenei said Israel should "expect a severe punishment" in the face of the early morning strikes which "struck residential centers."
"Several commanders and scientists were martyred in the enemy's attacks," Khamenei said. "Their successors and colleagues will immediately resume their duties… with this crime, [Israel] has prepared a bitter and painful fate for itself, which it will definitely see."
Iran's foreign ministry said that Iran "has the legal and legitimate right to respond" to the Israeli attacks "in accordance with Article 51 of the United Nations Charter," and called on the president of the UN Security Council "to take immediate action" to confront Israel's aggression "as soon as possible."
Article 51 states that "nothing in the present charter shall impair the inherent right of individual or collective self-defense if an armed attack occurs against a member of the UN, until the security council has taken measures necessary to maintain international peace and security."
'Not involved'
The US said it was not involved in the Israeli strikes and advised Tehran not to retaliate against US personnel in the Middle East.
"Israel advised us that they believe this action was necessary for its self-defense," secretary of state Marco Rubio said, adding that the Trump administration has "taken all necessary steps to protect our forces and remain in close contact with our regional partners."
Iran's defense minister Aziz Nasirzadeh just this week warned that Iran could and would target US bases in the region if conflict was "imposed on us."
The US administration appeared to have at least advance warning of the imminent attack and on Wednesday ordered non-essential US personnel in Iraq and Israel to evacuate immediately.
Less than a day before the Israeli attack, Trump told reporters at the White House that he advised Israel against striking Iran as it may jeopardize his diplomacy with Tehran. US and Iranian diplomats were scheduled to meet on Sunday for another round of talks on a new deal to curb Tehran's nuclear program.
As long as the US and Iran are negotiating, "I don't want [Israel] going in because, I mean, that would blow it," Trump said. "Might help it actually but it also could blow it."
Crude oil futures surged in early Asian trading following news of the attacks. The front-month August Ice Brent contract rose by as much as 13pc to a high of $78.50/bl in early trading. July WTI futures on Nymex traded as high as $77.62/bl.