By Ahmed Rasheed and Ahmed Aboulenein
BAGHDAD (Reuters) - Iran vowed harsh revenge after the United States killed Iranian Major-General Qassem Soleimani, head of the elite Quds Force and architect of Iran's spreading military influence in the Middle East, in an air strike on Friday at Baghdad airport.
Soleimani's killing, authorized by President Donald Trump, marked a dramatic escalation in the regional "shadow war" between Iran and the United States and its allies, principally Israel and Saudi Arabia.
Top Iraqi militia commander Abu Mahdi al-Muhandis, an adviser to Soleimani, was also killed in the attack.
Iran has been locked in a long conflict with the United States that escalated sharply last week with an attack on the U.S. embassy in Iraq by pro-Iranian militiamen following a U.S. air raid on the Kataib Hezbollah militia, founded by Muhandis.
"At the direction of the president, the U.S. military has taken decisive defensive action to protect U.S. personnel abroad by killing Qassem Soleimani," the Pentagon said in a statement.
"This strike was aimed at deterring future Iranian attack plans," it added.
U.S. officials, speaking on the condition of anonymity, said was killed in a drone strike. Iran's Revolutionary Guards said he was killed in an attack by American helicopters.
Iraqi paramilitary groups said three rockets landed near Baghdad airport's cargo terminal, hitting two vehicles and killing five Iraqi paramilitary men and two "guests".
Pictures showed burning debris on an airport road.
Oil prices were up nearly $3 on the news.
Iran's Supreme Leader Ayatollah Ali Khamenei said harsh revenge awaited the "criminals" who killed Soleimani. His death, though bitter, would double the motivation of the resistance against the United States and Israel, he said.
In a statement carried by state television he called for three days of national mourning.
Soleimani, who led the Quds Force, the foreign arm of the Revolutionary Guards and had a key role in fighting in Syria and Iraq, had acquired celebrity status at home and abroad. Over two decades he had been at the forefront of projecting the Islamic Republic's military influence across the Middle East.
MOURNING IN IRAN
Iranian state television presenters wore black and broadcast footage of Soleimani peering through binoculars across a desert and greeting a soldier, and of Muhandis speaking to followers.
President Hassan Rouhani said the assassination would make Iran more decisive in its resistance to the United States while Iran's Revolutionary Guards said anti-U.S. forces would exact revenge across the Muslim world.
Trump, who is facing impeachment charges, made no immediate comment but posted a picture of the U.S. flag on Twitter.
U.S. House of Representatives Speaker Nancy Pelosi, a Democratic and strong critic of the Republican president, said the attack was carried out without consultation with Congress and without authorization for the use of military force against Iran.
Iraqi Prime Minister Adel Abdul Mahdi condemned the killings as a violation of the conditions of the U.S. military presence in Iraq and an act of aggression that breached Iraq's sovereignty and would lead to war.
Iraqi Shi’ite cleric Moqtada al-Sadr, who portrays himself a nationalist rejecting both Iranian and U.S. influence, ordered his followers to be ready to defend Iraq and urged all sides to behave wisely.
The Syrian government of President Bashar al-Assad, long supported by Iran, condemned what it called criminal U.S. aggression.
In Israel, the government of Prime Minister Benjamin Netanyahu - which has long regarded Soleimani as a major threat - gave no immediate response to his death but Israel Army Radio said the military had gone on heightened alert.
The slain commander's Quds Force, along with its stable of paramilitary proxies from Lebanon's Hezbollah to Iraq's Popular Mobilisation Forces grouping of Iran-backed militias - battle-hardened militias armed with missiles - has ample means to launch a multi-pronged response.
In September, U.S. officials blamed Iran for a devastating missile and drone attack on oil installations of Saudi Aramco (SE:2222), the Saudi state energy giant and world's largest oil exporter. The Trump administration did not respond, beyond heated rhetoric and threats.
Iran, for its part, has absorbed scores of air strikes and missile attacks, mainly carried out by Israel against its fighters and proxies in Syria and Iraq.
But analysts say Iran is likely to respond forcefully to the targeting of Soleimani, who it has built into a legend as its influence has spread across the region in the wake of the U.S.-led invasion of Iraq in 2003 and subsequent occupation
Soleimani had survived several assassination attempts against him by Western, Israeli and Arab agencies over the past two decades.
The Quds Force, tasked with carrying out operations beyond Iran's borders, shored up support for Syria's Assad when he looked close to defeat in the civil war raging since 2011 and also helped militiamen defeat Islamic State in Iraq.
Soleimani became head of the force in 1998, a position in which he kept a low profile for years while he strengthened Iran's ties with Hezbollah in Lebanon, Syria's government and Shi’ite militia groups in Iraq.
IRAQI PARAMILITARY GROUPS
Muhandis, who was killed with Soleimani, oversaw Iraq’s PMF, a grouping of paramilitary groups mostly consisting of Iran-backed Shi’ite militias that was formally integrated into Iraqi armed forces.
His Kataib Hezbollah militia, which received battlefield training from Lebanon’s Hezbollah, has long targeted U.S. forces and was one of the earliest groups to send fighters to Syria to support Assad.
In 2009, Washington declared Kataib Hezbollah a foreign terrorist organization, saying it threatened stability in Iraq and declared Muhandis a terrorist. In 2007, a Kuwaiti court sentenced him to death in absentia for his involvement in the 1983 U.S. and French embassy bombings in Kuwait.
Iran's ambassador to Iraq told state television that Soleimani's body would be sent to Iran.