Tens of thousands of people have taken to the streets of Tehran to protest against US "crimes" after an airstrike ordered by President Donald Trump .
Chanting "Death to America" and holding up posters of the slain commander, Qasem Soleimani, the demonstrators filled streets for several blocks in central Tehran after Friday prayers.
The Islamic Revolutionary Guard Corps confirmed the commander of its Quds Force foreign operations arm .
After the Soleimani assassination last January, Tehran abandoned its commitments to the nuclear deal. Source: AAP
Women and men, many of them elderly, took part in the procession, some holding up portraits of Iran's supreme leader Ayatollah Ali Khamenei.
"The axis of any evil is America, the motto of religion and the Koran is death to America," they said in unison.
"O leader of our revolution, condolences, condolences."
State news agency IRNA said there were similar demonstrations in the cities of Arak, Bojnourd, Hamedan, Hormozgan, Sanandaj, Semnan, Shiraz and Yazd.
Thousands of Iranians take to the streets to mourn the death of commander of the Quds Force Qasem Soleimani. Source: AAP
News of the death of General Soleimani, one of Iran's most popular public figures, also saw people hold impromptu gatherings in his central hometown of Kerman.
The Pentagon said US President Donald Trump had ordered General Soleimani's "killing" after a pro-Iran mob this week laid siege to the US embassy in the Iraqi capital.
Iran's supreme leader Ayatollah Ali Khamenei swiftly vowed "severe revenge" for General Soleimani's death, the biggest escalation yet in a feared proxy war between Iran and the US on Iraqi soil.
As the US embassy urged all American citizens to leave Iraq "immediately", Mr Trump tweeted a picture of the US flag without any explanation.
'Dangerous escalation'
General Soleimani headed the Islamic Revolutionary Guard Corps' Quds Force foreign operations arm and also served as Iran's pointman on Iraq, visiting the country in times of turmoil.
The Pentagon said General Soleimani had been "actively developing plans to attack American diplomats and service members in Iraq and throughout the region".
It said it took "decisive defensive action to protect US personnel abroad by killing Qasem Soleimani," but did not specify how.
Iran's Foreign Minister Mohammad Javad Zarif slammed the US strike as "extremely dangerous and a foolish escalation," as three days of mourning were declared.
The Iraqi Prime Minister said the strike was a "flagrant violation" of a security accord with the US, warning it would "spark a devastating war in Iraq".
A paramilitary group, Asaib Ahl al-Haq, urged its fighters to be on high alert while militiaman-turned-cleric Moqtada Sadr reactivated his Mahdi Army, nearly a decade after dissolving the notoriously anti-American force.
And in Lebanon, the leader of the Tehran-backed Hezbollah group, Hassan Nasrallah, warned of "punishment for these criminal assassins".
But there were daring celebrations in Baghdad's Tahrir Square, the epicentre of a three-month-old protest movement that has slammed the Iraqi government as corrupt and beholden to Iran.
"Oh Qasem Soleimani, this is a divine victory," demonstrators chanted as some danced in the streets.
'Decapitation strike'
Analysts said the strike - which sent world oil prices soaring - would be a game-changer in the tensions between Iran and the US.
A burning vehicle near Baghdad International Airport, Iraq on Friday. Source: Supplied
"Trump changed the rules - he wanted [General Soleimani] eliminated," Ramzy Mardini, a researcher at the US Institute of Peace, said.
General Soleimani "didn't appreciate that his actions of threatening another hostage crisis at the (US) embassy changed the way things were going to be done," Mr Mardini said.
Phillip Smyth, a US-based specialist in Shiite armed groups, described the strike as "the most major decapitation strike that the US has ever pulled off".
He told AFP it would have "bigger" ramifications than the 2011 US operation that killed Al-Qaeda chief Osama bin Laden and the 2019 American raid that killed Islamic State group Abu Bakr al-Baghdadi.
"There is no comparison," Mr Smyth added.
The developments come after an unprecedented attack on the US mission in Baghdad.
