The United States has launched the first air strike against Islamic militants in Iraq, the Pentagon has announced.
The air strikes on Friday took place shortly following the start of relief supplies dropped by air to beleaguered Yazidi refugees fleeing militants in Iraq.
The Pentagon said two US fighter jets dropped bombs on Islamist militants in Iraq towing artillery outside Arbil near US personnel.
Pentagon press secretary Rear Adm. John Kirby says two F/A-18 jets dropped 500-pound bombs on a piece of artillery and the truck towing it.
He said the Islamic State of Iraq and the Levant (Isil) had been using the artillery to shell Kurdish forces defending Arbil where US personnel are located.
"The decision to strike was made by the US Central Command commander under authorisation granted him by the commander in chief," he said.
In briefing on Friday, White House Press Secretary Josh Earnest has outlined US priorities in Iraq: Protecting US personnel in Erbil, aiding humanitarian situation, backing Iraq security force.
Rearming Kurds considered
A Pentagon spokesman said, meanwhile, that rearming outgunned Kurds is "something we are certainly considering and talking about".
US lawmakers expressed support for the action. In a statement Sen. Dianne Feinstein, D-California, said: "I strongly support the president's authorisation for airstrikes against [Islamic State]. This is not a typical terrorist organization - it is a terrorist army, operating with military expertise, advancing across Iraq and rapidly consolidating its position."
House Majority Leader Kevin McCarthy, R-California, says he supports targeted air strikes in Iraq; "Frankly the threat posed by [Isil] requires a more fullsome response and a more comprehensive plan than has thus far been put forward' by Obama administration."
On Thursday, US President Barack Obama authorised air strikes on Iraq to protect Christians and prevent "genocide" of tens of thousands of members of an ancient sect sheltering on a desert mountaintop from Isil fighters threatening to exterminate them.
Obama said he had authorised limited bombing to blunt the onslaught of militants who have captured swathes of northern Iraq and advanced to a half-hour drive from the Kurdish regional capital, Arbil.
It was the first time since the Islamists — an offshoot of Al Qaida — began a lightning offensive in June, overrunning swathes of northern and western Iraq and declaring a “caliphate” in captured areas of Iraq and Syria, that the United States has opted for military action.
Deeply reluctant to engage US forces in the Middle East again after costly wars in Iraq and Afghanistan, Obama said he had approved a “targeted” use of air power to protect US personnel if Isil militants advance further towards Arbil, seat of the Kurdistan regional government.
He made a late-night television address after the first US transport planes dropped food and water to members of the Yazidi ethno-religious minority sheltering in hostile mountain terrain after the Islamists captured their home town of Sinjar.
Reuters photographs on Thursday showed the insurgents had raised their black flag over a checkpoint just 45km from Arbil, bringing them closer than ever to the city of 1.5 million that is also the region’s economic capital.
The Islamists’ advance and the threat of US military action sent shares and the dollar tumbling on world financial markets, as investors moved to safe haven assets such as gold and German government bonds.
US oil majors Exxon Mobil and Chevron operating in Iraqi Kurdistan evacuated expatriate staff on Thursday, industry sources said, and the shares of several oil companies operating in the region fell for a second day on Friday.
However, a spokesman for Austria’s OMV energy company, which has worked in the region since 2008, said the Islamists’ advance was having no impact on its operations.
“Everything for us is under control,” he said.
Obama said air strikes, which would be the first by the US military in Iraq since its withdrawal in 2011, could also be used to support Iraqi and Kurdish forces trying to break the Islamists’ siege of Sinjar mountain, where tens of thousands of Yazidis have taken refuge.
“Earlier this week, one Iraqi in the area cried to the world, ‘There is no one coming to help’,” said Obama. “Well, today America is coming to help.”
Yazidis, ethnic Kurds who practice an ancient faith related to Zoroastrianism, are among a handful of pre-Islamic minority groups who survived for centuries in northern Iraq. They are believed to number in the hundreds of thousands, most living in Iraq, with small communities in the Caucasus and Europe.
“We can act carefully and responsibly to prevent a potential act of genocide,” said Obama, calling the militants “barbaric.”
US officials also announced an acceleration of military supplies to the Kurdish regional government, whose peshmerga forces have been routed by the Islamists as they seized control of a dozen towns and the country’s biggest dam in the last week.
Obama insisted he would not commit ground forces and had no intention of letting the United States “get dragged into fighting another war in Iraq”.
The US Defence Department said planes dropped 72 bundles of supplies, including 8,000 ready-to-eat meals and thousands of gallons of drinking water, for threatened civilians near Sinjar.
Northern Iraq has long been one of the most diverse parts of the Middle East, home to isolated ethnic and religious minorities who survived centuries of pressure to assimilate into the Arabic-speaking Muslim world.
Tens of thousands of Iraqi Christians have also fled for their lives after Islamic State fighters overran their hometown of Qaraqosh on Thursday.
Neighbouring Iran, which along with Washington had backed Al Maliki, is working diplomatically to try to find a less polarising figure who can united Iraq’s sectarian factions.
Tehran has also sent elite Revolutionary Guard officers to help organise the defence of Baghdad, Iranian sources say.
Obama sent a small number of US military advisers in June in an effort to help the Iraqi government’s efforts to fend off the Islamist offensive.
The Islamists’ latest gains sparked an international outcry.
UN Secretary-General Ban Ki-moon said he was “deeply appalled” by the attacks by Isil militants. The UN Security Council condemned the group and called on the international community to support the Iraqi government.