Blasts were reported in Tehran and at a key uranium enrichment site. Here is what we know:

What was hit?

Israel's military said its jets carried out strikes on "dozens of military targets, including nuclear targets in different areas of Iran".

It said 200 jets were involved in the raids, striking about 100 targets.

Blasts were reported in the capital, where state television said fire and smoke were seen at a key site for Iran's Islamic Revolutionary Guard Corps in the city's east.

Damage to residential buildings and civilian deaths were also reported.

State television said Natanz, in Iran's central Isfahan province and home to a key nuclear site, had been hit "several times", showing footage of heavy smoke billowing from the site.

The UN nuclear watchdog confirmed Natanz was among the sites targeted in the attacks and said it was in touch with Iranian authorities and its inspectors in the country "regarding radiation levels".

Additional strikes were reported against three military sites in Iran's northwest.

Iranian state media confirmed the deaths of Revolutionary Guards chief Hossein Salami and armed forces chief of staff Mohammad Bagheri in the attacks.

It also reported 50 people, including women and children, had been injured.

Why now?

Israel sees the cleric-run state in Tehran as an existential threat.

It says it took out Iran's air defences in October last year in retaliation for a barrage of about 200 missiles from the Islamic republic.

Defence Minister Israel Katz described the Israeli action as a "pre-emptive strike". The army said intelligence showed Iran was approaching a "point of no return" on its nuclear programme.

The United States and other Western countries, along with Israel, have repeatedly accused Iran of seeking a nuclear weapon, which it has always denied.

Israel again called for global action after the UN's International Atomic Energy Agency (IAEA) accused Iran on Wednesday of non-compliance with its obligations.

There had been indications a military strike was likely, with US media reporting an imminent Israeli attack that would not be coordinated with the Washington.

"I don't want to say imminent, but it looks like it's something that could very well happen," US President Donald Trump told reporters on Thursday when asked if an Israeli attack loomed.

A sixth round of talks over Tehran's nuclear programme had been scheduled between the United States and Iran on Sunday in Oman.

Trump said after the strikes he was "still hoping" for talks.

Who was involved?

Israel relies on the United States for military and diplomatic support but carried out the strikes alone, top US diplomat Marco Rubio said.

"We are not involved in strikes against Iran and our top priority is protecting American forces in the region," he said in a statement warning Tehran against targeting US interests.

Rubio said Israel had "advised us that they believe this action was necessary for its self-defence," without offering support or criticism of the strikes.

Trump meanwhile told Fox News that he had advance notice of the strikes, warning Tehran "cannot have a nuclear bomb".

Tehran said Washington would be "responsible for the consequences" of Israel's deadly attacks, saying they "cannot have been carried out without the coordination and permission of the United States".

What reaction has there been?

Oman, due to host nuclear talks this weekend, called the strikes a "dangerous escalation" that threatened negotiations and regional stability.

Saudi Arabia meanwhile condemned the "blatant Israeli aggressions".

Netanyahu said the strikes had been "very successful... and with God's help, we will achieve much more".

Air traffic was halted at Tehran's main international airport, and neighbouring Iraq closed its airspace entirely.

Israel warned Iran could retaliate at any moment, declaring a state of emergency and also shutting its airspace.

In Washington, the White House said Trump would convene security chiefs after the strike, which was criticised by a senior Democrat.

"Israel's alarming decision to launch airstrikes on Iran is a reckless escalation that risks igniting regional violence," said Senator Jack Reed, the top Democrat on the US Senate Armed Services Committee.

The strikes saw oil prices surge up to 12 percent, though Iran's oil ministry said there had been "no damage" to refineries or depots.

burs-sah/dv