Armored convoys roared down desert highways and plumes of black smoke rose in the distance as Iraqi and Kurdish forces launched a long-awaited operation on Monday to drive the Islamic State group from Mosul, the country's second largest city.
More than 25,000 troops, including Iraqi soldiers, Sunni tribal fighters, Shiite militias, Kurdish and U.S. forces will take part in the operation, the most complex since American troops withdrew from Iraq five years ago. The battle could take weeks or even months, and it's not clear how soon before any of the forces enter the city.
IS group captured Mosul in the summer of 2014 when it swept across northern and western Iraq, and it was there that IS leader Abu Bakr al-Baghdadi first announced a self-styled caliphate, which at that time stretched across a third of both Syria and Iraq.
But over the past year the extremist group has suffered a series of defeats, and in Iraq it is now mostly confined to Mosul and some smaller nearby towns.
The forces converging on Mosul wave a variety of flags, including the Kurdish regional flag and Shiite religious banners. The complex makeup of the combined force and past animosities have raised concerns that Mosul's liberation could ignite new conflicts.
Here is a set of AP images from near the front lines.