Iraqi security forces have slowed the advance of insurgents and have killed 279 “terrorists” in the last 24 hours, according to a spokes person. The Iraqi government forces have been aided by Shia Muslim and Kurdish militias.

The Sunni rebels, including the Islamic State in Iraq and the Levant (ISIS) still control key town Tikrit and Mosul.

The Pentagon has said a US aircraft carrier has been dispatched to the Gulf as a precautionary measure. The USS George HW Bush is being accompanied by tow missile ships.

The most senior Shia cleric in Iraq, Grand Ayatollah Al al-Sistani, has called on all the Shia population of Iraq to take up arms to battle the Sunni insurgents. Reports suggest thousands of Shia men have answered the call and joined militias to defend their towns and cities from the Sunni advance.

The insurgents have advanced rapidly in the past week and made it as far as within 80km of Baghdad. However, that advance now appears to have been slowed.