BAGHDAD - Islamic militants on Monday captured the city of Tal Afar in northern Iraq. Tal Afar is on a highway linking the Iraqi city of Mosul, which was captured last week, to Syria.
These are the areas they hold so far. The militants are known as ISIS - an acronym for Islamic State of Iraq and Syria. Their goal is to form an Islamist state, ruled by shariah law, in parts of Iraq and Syria.
As ISIS captured yet another city in the north, its fighters were starting to use their new equipment, abandoned by the fleeing Iraq army.
But it's these images that have really shocked the people of Iraq and threaten to plunge this country deeper into sectarian bloodshed. ISIS claims the photos show its fighters executing more than 1,700 men captured in last week's fighting.
The United Nations on Monday verified the photos and said they were evidence of war crimes.
Pictures and videos like these, of militants brutalizing Iraqi soldiers, have horrified Shiites, and Sunnis are now living in fear of retribution - especially here in Baghdad, a deeply divided city.
These walls were built years ago to separate Sunni and Shiite neighborhoods, during the worst period of sectarian bloodletting. Now communities on both sides fear that violence will explode here again.
In the Shiite stronghold of Sadr City, men took to the streets with every weapon they could find, in a show of force.
We found tribal leader Abu Ali Khalek leading a chant that summed it all up. "ISIS, we will kick you out!" he shouted in Arabic.
Abu Ali claims 1 million men have volunteered to join the fight.
"There is a pressing need to defeat terrorism and back the army," he said."The army is strong."
But if the army was as strong sa he says, would there be a need for these militias?
"The army was betrayed in Mosul," Abu Ali said, "and so they need backup. Iraq will not be broken. Iraq is strong."