Iraqi PM Nouri Maliki has fired senior officers for failing to halt a sweeping advance by Sunni Islamist rebels.
Four army commanders were dismissed for failing to perform "their national duty", a government statement said on Tuesday.
Iraqi forces have been engaged in heavy clashes with the rebels who have seized several key cities in the past week.
The US is deploying up to 275 military personnel to protect staff at its huge embassy in the capital, Baghdad.
The militants, led by the Islamic State in Iraq and the Levant (ISIS), took control of the northern cities of Mosul and Tikrit in a rapid advance last week, and Tal Afar on Monday.
They also briefly captured parts of the city of Baquba - just 60km (37 miles) from Baghdad - in an overnight assault, before government troops and allied Shia militia regained control on Tuesday.
Qasem Suleimani, the commander of an elite unit of Iran's revolutionary guards, is reported to be in Baghdad, helping military and Shia leaders co-ordinate their campaign against the rebels.
