The battle reportedly started Saturday and lasted into early Sunday, resulting in about 250 casualities among the insurgents and about 25 casulties among the Iraqis.
Juan Cole tries to sort out the various confusing reports:
It seems most likely that this was Shiite on Shiite violence, with millenarian cultists making an attempt to march on Najaf during the chaos of the ritual season of Muharram. But who knows? It is also possible that the orthodox Shiites in control of Najaf hate the heretic millenarians and the threat of the latter was exaggerated. Darned if I know. The reports of the Army of Heaven being so well armed make no sense if it was a ragtag millenarian band. But those reports could be exaggerations, too.It seems highly likely to me that these first reports are more propaganda than truth at the moment. Later reports may clarify what actually happened.
It seems most likely that the Mahdawiya is the sect of Sheikh Mahmud al-Hasani al-Sarkhi and that al-Basri was the founder of the sect. That would be a way of reconciling al-Zaman with al-Hayat.
The dangers of Shiite on Shiite violence in Iraq are substantial, as this episode demonstrated. Ironically, given Bush's mantra about Iran, the trouble makers here are a sect that absolutely hates Iran.
Addendum 6:20PM CST
The discussion of the actions of the Iraqi Army at Kurballa assumes that since the Iraqi's were repelled after the first attack on the militant sect, they did not perform well. The fact is that they apparently were unaware of the size, training, equipment and level of organization when they first attacked.
There is nothing unusual about this kind of situation. A well-trainined and organized force meeting such resistance has preplanned reserves to call on. The Iraqis in this case did. First there was an Iraqi strike brigade, and then they called on aerial support from the U.S. Army and Air Force. After that, even more was needed so they called in U.S. Army tanks and artillery.
Nothing in the reports that have been received so far suggests that the Iraqi forces failed to fight or were untrained. This pattern of calling in reserves to provide greater and greater force to apply to the enemy is exactly what the U.S. Army would have done in the same circumstances.
That's not to say that there were no failures. Reports from Karballah have been conflicting and unreliable, so we may hear something solid later. My point is that nothing we have heard so far suggests that the enemy (insurgents? an Islamic Mellenial sect? No one is sure yet.) was too tough for the Iraqi forces. What we have heard so far is the way the Iraqi Army should have functioned in combat.