The Battle for Sadr City is on. Several weeks ago, U.S. and Iraqi forces took control of the southern third of the city and began constructing concrete barriers to secure the area. Since U.S. and Iraqi forces moved into Sadr City, units have conducted patrols and distributed humanitarian aid to the Iraqis living in the neighborhoods. The U.S. military is also conducting aerial patrols of Sadr City, and is striking at Mahdi Army fighters as they plant roadside bombs, move weapons, and gather for attacks.

This has provoked a violent response from Muqtada al Sadr's Mahdi Army, which is struggling to prevent the Iraqi government from maintaining a foothold in Sadr's power base in Baghdad. Over the past several days, Mahdi Army fighters have grouped for mass attacks. Each time U.S. and Iraqi forces beat them back, inflicting heavy losses on the enemy while suffering few of their own.

One of the largest engagements occurred today. A large force of Mahdi Army fighters ambushed a U.S. patrol on the border area where the wall is being built. U.S. forces responded and killed 28 Mahdi Army fighters while suffering six wounded. None of the casualties are life-threatening. On Sunday, 22 Mahdi Army fighters were killed as they massed to strike at a checkpoint in Sadr City. Sixteen more were killed in separate engagements that same day.

There have been numerous other air and ground engagements with the Mahdi Army in Sadr City and the surrounding areas over the past several weeks. Since Sadr threatened to conduct a third uprising nine days ago, U.S. and Iraqi troops have killed 186 Mahdi Army fighters in Baghdad alone. Prime Minister Nouri al Maliki has said he is serious about taking control of Sadr City and disarming and disbanding the Mahdi Army. There are no signs that he plans to halt the offensive.