• Militants from the Islamic State of Iraq and the Levant (Isis) seize two new towns in the Diyala province, Saadiya and Jalawla, but Kurdish Peshmerga fighters manage to retake Jalawla from the Sunni militants.
  • In northern Iraq, Kurdish security forces move to fill the power vacuum taking over air base and other posts abandoned by the military in Kirkuk.
  • US President Obama says he doesn't rule out any option in response to the crisis.
  • Baghdad authorities tighten security and urge Iraqis to help battle the insurgents. Residents in the capital stock up on essentials.
Fighters of the Islamic State of Iraq and the Levant (Isis) celebrate on vehicles taken from Iraqi security forces, at a street in city of Mosul, Reuters

17:55 Live coverage ends here for today. Check IBTimes UK for all the latest developments on the Iraq crisis.

17:35 President Obama calls Iraqi leaders to join forces to fight Isis, as the US "is not going to do it for them."

"Given the very difficult history that we've seen in Iraq ... Various military actions by the United States, by any outside nation are not going to solve those problems in the long-term ... or provide stability that we need," Obama says.

"Look, the US has poured a lot of money into these Iraqi security forces ... the fact that they're not willing to stand and fight and man their posts ... indicates that there's a problem with morale, there's a problem in terms of commitment, and ultimately that's rooted in the political problems that have plagued the country for a very long time."

17:08 President Obama tells reporters the US will not take action without "a political plan by the Iraqis" to reunite the country. He adds that a decision about US military action "is going to take several days".

"This is not something that's going to happen overnight. The US is not simply going to involve itself in a military action in the absence of a political plan by the Iraqis that assures us that they are willing to work together."

16:44 The US is considering an air assault on Islamic extremists in Iraq and Syria, the Guardian reports.

16:35 Kurdish Peshmerga fighters retake Jalawla, Reuters reports.

16:22 According to Charles Lister, visiting fellow at the Brookings Doha Centre, there are an estimated 7,000 to 8,000 Isis forces in Iraq and 5,000 in Syria.

16.10 Iraqi foreign minister Hoshyar Zebari has compared the government forces' retreat to that of Saddam Hussein's troops in the face US forces in 2003.

"It is the same collapse that happened in the ranks of the Iraqi armed forces when American forces entered Iraq," Zebari was quoted as saying by the Daily Telegraph.

"[They] took off military uniforms and put on civilian clothes and went to their houses, leaving weapons and equipment [behind]."

16.02 Activists say that Isis forces have kidnapped thousands of people in Syria.

The UK-based Syrian Observatory for Human Rights says: "[We] call for the release of more than 2,000 persons kidnapped by the Isis in Aleppo, al-Hasaka, al-Raqqa and Deir Izzor.

"The kidnapped include more than 500 Syrian Kurds as well as the prominent Human Rights activist Abdallah al-Khalil."

14.59 In this photo, members of Iraqi security forces are seen as they stand guard during an intensive security deployment in Kerbala, southwest of Baghdad.

Iraq crisis troops ISIS ISIL

14.57 Journalist Zaid Benjamin ‏tweets:

14.52 There are reports that access to twitter and other social media has been blocked in parts of Iraq by the government. Read more here.

14.50 Local officials and witnesses tell Reuters that Iraqi army helicopters have fired rockets on a mosque in Tikrit.

14.47 UN High Commissioner for Human Rights Navi Pillay on Iraq:

The full extent of civilian casualties is not yet known but reports suggest the number of people killed in recent days may run into the hundreds, and the number of wounded is said to be approaching 1,000," Pillay says.

"Isis fighters, including prisoners they had released from jails in Mosul and provided with arms, have been actively seeking out -- and in some cases killing -- soldiers, police and others, including civilians, whom they perceive as being associated with the Government."

14.44 After talks with US Secretary of State John Kerry, British Foreign Secretary William Hague says: "We are not planning a British military intervention, but we are looking urgently at other ways to help, for example with counter-terrorism expertise.

14.38 UN human rights spokesman Rupert Colville says his office has reports jihadist militants who overran Mosul executed dozens of people, including 17 civilians working for the police and a court employee.

Four women have killed themselves after being raped, Colville says.

13.56 More on Iraq's most senior Shia cleric issuing a call to arms against Isis: Shia cleric Sheik Abdul-Mahdi al-Karbalaie has told worshippers that it is their civic duty to confront insurgents.

"Citizens who can carry weapons and fight the terrorists in defence of their country, its people and its holy sites should volunteer and join the security forces," al-Karbalaie says.

Al-Karbalaie represents Grand Ayatollah Ali al-Sistani, the most revered Shiite spiritual leader in Iraq.

13.38 Kerry says Isis is "terrorising" the whole Iraqi population. He describes the group as an "enemy of pluralism and decency".

13.36 US Secretary of State John Kerry has commented on the crisis in Iraq on the sides of the End Sexual Violence in Conflict summit in London.

Kerry says no regional power in the Middle East benefits from the Islamist insurgency.

"No country benefits from what is happening," Kerry says citing Iran, Israel and Lebanon as examples.

Kerry says that Isis is so extreme that even al-Qaeda dissociated from them.

He says Isis represents a threat "not only to the Middle East but also to Europe, the US and other countries in the world".

13.10 Iran's Supreme Leader Ayatollah Ali Khamenei tweets:

13.02 Fresh clashes between Isis and Iraqi Shia militia are reported in the towns of Udhaim, 60 miles north of Baghdad and in Muqdadiya, 50 miles northeast of the capital.

12.39 In this photo, Kurdish Iraqi security forces are seen as they patrol a street in the northern oil city of Kirkuk.

Kirkuk Iraq

12.35 Swedish foreign minister Carl Bildt tweets:

12.33 Germany's foreign minister says that it will be hard to prevent Iraq from splitting up.

Frank-Walter Steinmeier says: "[Isis] has reached a potential that goes far beyond terrorist attacks."

Steinmeier describes the predominantly Sunni jihadist group as "a power factor that we will have to deal with not just in Iraq but in the entire region in future."

"This won't make a political solution and the prevention of a splitting up of Iraq any easier."

12.18 NBC chief foreign correspondent Richard Engel tweets:

12.08 Iraq's most senior Shia cleric has called on the people of Iraq to take up arms and defend the country against the Sunni-led insurgency.

Iraq's Grand Ayatollah Ali al-Sistani, the highest ranking Shia authority in Iraq, made the call to arms as Islamist militants with the Islamic State of Iraq and the Levant (Isis) continue to advance on Baghdad.

Read more here.

12.02 David Andrew Weinberg, a senior fellow at the Foundation for Defense of Democracies tweets:

11.59 In this photo, volunteers who have joined the Iraqi Army to fight Isis are seen as they board army trucks in Baghdad.

Iraq Crisis Isis

11.52 Saddam Hussein's daughter says she is pleased with the advances made by Isis in Iraq.

"I am very happy with the victories (which) were achieved by my father's men," Raghad Saddam Hussein is quoted as saying by Al Quds Al Arabi newspaper.

A former top military commander and vice president in the Hussein government, Izzat Ibrahim al-Douri, and his men have joined forces with the jihadists.

11.36 Brigadier General Saad Maan from the Iraqi Interior ministry details the government's plan to defend Baghdad to AFP.

"The plan consists of intensifying the deployment of forces, and increasing intelligence efforts and the use of technology such as (observation) balloons and cameras and other equipment," Maan says.

11.27 Isis counts on many foreign fighters and has a pervasive social media presence. This account said to be Isis-related tweets:

11.21 Here is a profile of Isis secretive leader Abu Bakr al-Baghdadi.

Al-Baghdadi has the reputation of a highly organised and ruthless battlefield tactician who rarely appears in the media.

There are only two authenticated photographs of him, and unlike al-Qaeda leaders such as Osama Bin Laden and Ayman al-Zawahiri, he does not appear in video messages.

11.14 Isis next target is said to be the city of Samarra, which is home to a revered Shia shrine and is believed to be the hometown of Isis chief, Abu Bakr al-Baghdadi.

Shia fighters are reportedly travelling to the city to fight.

11.12 AFP reports that news photographer Kamran Najm Ibrahim was killed while covering fighting between Kurdish security forces and Isis in northern Iraq on, west of the oil city of Kirkuk.

11.01 The UN says the militants carried out summary executions in Mosul, including 17 civilians killed in one street. Both civilians and Iraqi soldiers have been reportedly targeted.

10.45 The UN says Iraq's refugee population has rocketed to almost 800,000 after Isis insurgency.

The UN refugee agency, UNHCR, say 300,000 people fled for safety this week in Erbil and Duhok.

Another 480,000 people left their homes due to fighting since January.

10.39 Here is a video showing Isis fighters parading through the streets of Mosul. Some are aboard US made Humvees seized from the Iraqi army.

10.25 Yesterday was George Bush senior's 90th birthday.

The former president who oversaw the US first war in Iraq in 1990, celebrated by making a tandem parachute jump near his summer home in Maine.

Bush tweeted:

10.12 An Iranian official tells Reuters that Tehran is ready and willing to strike an unprecedented cooperation with the US to fight Isis.

"We can work with Americans to end the insurgency in the Middle East," the official said. "We are very influential in Iraq, Syria and many other countries."

Isis insurgents are mainly Sunni Muslims while Iraqi PM Al-Maliki leads a Shia government allied to Iran.

9.45 Iraqi police officials confirm cities of Saadiya and Jalawla have been taken over by Isis.

Officials speaking on condition of anonymity, tell AP that militants driving in machinegun-mounted pickups entered the two towns late Thursday.

Jalawla is 125 kilometres (80 miles) northeast of Baghdad, and Sadiyah, 95 kilometres (60 miles) north of the Iraqi capital.

The officials say there were no clashes, as Iraqi soldiers had abandoned their posts without any resistance.

Kurdish forces have also reportedly entered Jalawla and secured offices of Kurdish parties in the town. No clashes have been reported between the two groups.

9.13 AFP reports that government troops clash with militants advancing on the city of Baquba, 30 miles north of Baghdad.

9.11 Iran's president Hassan Rouhani tweets he has had a phone conversation with Iraqi PM Nouri Al-Maliki.

Tehran has reportedly deployed its elite Revolutionary Guards to help Iraqi troops defend Baghdad.

8.40 Home to a large Shiite population, Baghdad would be a far harder target for the militants who have so far stuck to the Sunni heartland.

A useful map of Iraq from Reuters shows the different ethnic religious areas and Isis gains.

In the north, Iraqi Kurds have seized control of Kirkuk, after government forces abandoned their posts.

Iraq Crisis Map

8.30 Overnight jihadist fighters with the Islamic State of Iraq and the Levant (Isis) took over the cities of Saadiya and Jalawla, in the Diyala province northeast of Baghdad.

After seizing Iraq's second largest city of Mosul, Isis has vowed to march on Baghdad.

Islamic State of Iraq and the Levant iraq
Fighters of the Islamic State of Iraq and the Levant (Isis) stand guard at a checkpoint in the northern Iraq city of Mosu Reuters

More on Iraq's most senior Shia cleric issuing a call to arms against Isis: Shia cleric Sheik Abdul-Mahdi al-Karbalaie has told worshippers that it is their civic duty to confront insurgents.

"Citizens who can carry weapons and fight the terrorists in defence of their country, its people and its holy sites should volunteer and join the security forces," al-Karbalaie says.

Al-Karbalaie represents Grand Ayatollah Ali al-Sistani, the most revered Shiite spiritual leader in Iraq.

4:37 Grand Ayatollah Ali al-Sistani, Iraq's most senior Shi'ite Muslim cleric, has urged followers to take up arms against Isis to topple Shi'ite Prime Minister Nuri al-Maliki, Reuters reports.

"People who are capable of carrying arms and fighting the terrorists in defence of their country ... should volunteer to join the security forces to achieve this sacred goal," said Sheikh Abdulmehdi al-Karbalai, delivering Sistani's message.

4:35 Kurdish Peshmerga fighters have taken over Saadiyah and Jalawla, previously invaded by Isis, Reuters reports.