In response to the uprising and growing strength of Muqtada al-Sadr, Task Force 1st Armored Division launched Operation Iron Saber. This operation was designed to use overwhelming firepower against the enemy, public relations to discredit Muqtada al-Sadr and to rebuild the Iraqi security forces. Operation Iron Saber focused heavily in the area south of Baghdad, in particular the cities of Najaf, Diwaniyah, Al Kut and Karbala where the Mahdi army was the strongest.

There was a great deal of urban combat and occasionally militiamen stationed themselves in mosques using them as staging grounds. However, this did not deter coalition forces from going after them. The Mahdi army eventually became entrenched in Najaf where they occupied the holy shrine of Imam Ali. By June, Muqtada al-Sadr had surrendered calling his forces to peacefully disband and leave the city. However, al-Sadr was not taken into custody by coalition forces but allowed to go free.

The Task Force 1st Armored Division estimated it had killed approximately seven thousand militiamen.