Iraq base attack: US launches retaliatory strikes on Iran-backed fighters
The US has launched retaliatory air strikes against a pro-Iranian militia group in Iraq, after a rocket attack killed two of its soldiers.
The strikes targeted five weapons storage facilities across the country, the US defence department said.
Two Americans and a British soldier were killed in Wednesday's rocket attack on the Camp Taji military base.
Earlier, a US commander said an Iranian-backed militia group was likely to have fired the rockets.
"The Iranian proxy group Kataib Hezbollah is the only group known to have previously conducted an indirect fire attack of this scale against US and coalition forces in Iraq," Central Command chief Gen Kenneth McKenzie told a Senate committee.
In a statement on Thursday evening, the defence department confirmed that a series of "defensive precision strikes" were carried out by manned aircraft against Kataib Hezbollah facilities.
"These include facilities that housed weapons used to target US and coalition troops," it said. "[The strikes] were defensive, proportional, and in direct response to the threat posed by Iranian-backed Shia militia groups."
"The United States will not tolerate attacks against our people, our interests, or our allies," Defence Secretary Mark Esper added. "We will take any action necessary to protect our forces."
The US has accused Iran-backed militias of 13 similar attacks on Iraqi bases hosting coalition forces in the past year.
The killing of an American civilian in one such incident in December triggered a round of violence which ultimately led Mr Trump to order the assassination of the top Iranian general Qasem Soleimani and Kataib Hezbollah commander Abu Mahdi al-Muhandis the following month.
What's the background?
Earlier on Thursday, the US-led coalition in the region denied carrying out air strikes on Iran-backed Iraqi Shia militiamen in eastern Syria.
A monitoring group reported that bases belonging to the paramilitary Popular Mobilisation force were hit on Wednesday night, killing 26 people. The Imam Ali military base, which is believed to have been built by Iran, was also targeted.
But it was not immediately clear who carried out the strikes.
These followed Wednesday's attack on the Camp Taji military base that killed two Americans and a British solider.
The Iraqi military base, which is about 15km (nine miles) north of the capital Baghdad, hosts foreign troops from the US-led global coalition against IS. Their mission is to train and advise Iraqi security forces.
A coalition statement said that at about 19:35 (16:35 GMT) on Wednesday Camp Taji was hit by approximately 18 Katyusha rockets. Three coalition personnel were killed and 12 others wounded, it added.
Iraqi journalist Ali Al Dulaimy, who filmed the attack from the nearby town of Baji, said he heard screams of panic from American troops inside the camp, and that he saw them rushing to put out fires.
UK Prime Minister Boris Johnson described the attack as "deplorable", while the US defence secretary said President Donald Trump had authorised a response and warned that all options were on the table.
The UK Ministry of Defence identified the British soldier who was killed as Lance Corporal Brodie Gillon, a Combat Medical Technician who served as a Reserve with the Scottish and North Irish Yeomanry.
The two American personnel who died were active-duty troops with the US Army and Air Force, a US military official told the New York Times.
Why is Iraq drawn into the US-Iran confrontation?
Tensions between the arch-foes intensified last year, after Iran-linked fighters targeted US military and civilian personnel in a series of rocket attacks. There were also unclaimed air strikes in Iraq targeting militia facilities and Iranian officials.
In late December, a rocket attack on an Iraqi military base killed a US civilian contractor. The US blamed the powerful Kataib Hezbollah militia, which is part of the Popular Mobilisation, and carried out air strikes on its bases in Iraq and Syria that left at least 25 fighters dead.
The US embassy in Baghdad was then attacked by crowds of protesters, and President Trump warned Iran it would "pay a very big price".
On 3 January, Mr Trump authorised a drone strike near Baghdad airport that killed Qasem Soleimani – commander of the Islamic Revolution Guard Corps' Quds Force and architect of Iranian policy in the Middle East – and Abu Mahdi al-Muhandis.
Five days later, Iran launched ballistic missiles at Iraqi bases hosting US forces. The attack left more than 100 US troops with traumatic brain injuries.
Iran's Supreme Leader, Ayatollah Ali Khamenei, said the missile attack was "a slap in the face" for the US and vowed to end the American presence in the region.
There are about 5,000 US personnel and hundreds more from other countries in Iraq. They are deployed at the request of the government, but the parliament passed a bill following Soleimani's killing demanding the invitation be rescinded.