20 June 2014
Last updated at 12:02
Islamist-led militants and pro-government forces are engaged in fierce battles for the Baiji oil refinery and Tal Afar airport in northern Iraq.
Baiji, Iraq’s biggest refinery, is surrounded by the rebels, who say they have seized most of Tal Afar airport.
The fighting comes a day after the US said it would send some 300 military advisers to help the fight against the insurgents.
President Barack Obama stressed that US troops would not fight in Iraq.
US Secretary of State Kerry is expected to travel to Iraq soon to press for a more representative cabinet, hoping this could ease tensions between the country’s rival Muslim sects.
Iraqi Prime Minister Nouri Maliki has been accused of pursuing anti-Sunni policies, pushing some Sunni militants to join the jihadist Islamic State of Iraq and the Levant (ISIS), which has made rapid advances in recent days.
About 500,000 people have fled their homes in the country’s second-largest city, Mosul, which ISIS captured last week.
Analysis: John Simpson, BBC News, Baghdad
President Obama’s statement wasn’t the lifeline the Iraqi government hoped for. They wanted immediate airstrikes to stop ISIS in its tracks.
Instead, they will get up to 300 military advisers, who will restore the backbone to the Iraqi National Army which it has been missing since the Americans withdrew. The promise of air strikes is there, but attacks by US planes or missiles will, it seems, be dependent on some clear improvement in the way Iraq is governed; even though Mr Obama wouldn’t say so.
He believes Prime Minister Nouri Maliki has endangered Iraq by ignoring Sunni concerns and governing in the interests of the Shia majority. Mr Maliki’s supporters deny this and say he won’t resign, but rivals to him are said to be emerging.
The least Mr Maliki will have to do is create a new and more inclusive government. Only then, perhaps, will the bombing start.
ISIS says it has downed two military helicopters around the Baiji refinery but this has not been independently confirmed.
The BBC’s Jim Muir in Irbil, northern Iraq, says it is thought the militants may have captured part of the vast oil complex.
They have also seized a disused chemical weapons factory in Muthanna, 70km (45 miles) north-west of the capital, Baghdad.
The US says it does not believe the site contains any material that the insurgents could use to make chemical weapons.
But state department spokeswoman Jen Psaki said: “We remain concerned about the seizure of any military site by” ISIS.
Iraq has asked the US for air strikes against the Sunni militants.
Mr Obama said the US was prepared for “targeted and precise military action, if and when” required, but he insisted there was “no military solution” to the crisis.
He also pointedly urged the Shia-led Iraqi government to be “inclusive”.
Mr Obama said it was not the US’s place to choose Iraq’s leaders but warned:
“Only leaders with an inclusive agenda are going to be able to truly bring the Iraqi people together.
“The United States will not pursue military actions that support one sect inside of Iraq at the expense of another,” Mr Obama said.
This satellite image, taken on Thursday, shows smoke billowing from the refinery
In addition to sending advisers, Mr Obama said that the US would be increasing intelligence efforts and setting up “joint operation centres in Baghdad and northern Iraq”.
Thousands of Shia from southern Iraq have volunteered to help the Iraqi army.
Shia militiamen have been sent to assist in the defence of the capital of Diyala province, which has in effect become a frontline, and the nearby city of Samarra, site of a major Shia shrine.
On Wednesday, the chairman of the US Joint Chiefs of Staff, Gen Martin Dempsey, warned that the US military still lacked sufficient intelligence to take action. He told a congressional hearing that pilots would have difficulty knowing who they were attacking from the air.
Thousands of Iraqi Shia have volunteered to join the army and help fight ISIS
Are you in Iraq or do you have family there? Have you been affected by recent events? You can send details of your experiences to [email protected] using ‘Iraq’ in the subject line.
Or get in touch using the form below.