American commanders say they are also asking tribal sheiks to recruit fighters.
To encourage cooperation, Colonel Norris organized a meeting of tribal sheiks and neighborhood leaders.
At the time of the incident, tribal sheiks were scheduled to gather for a meeting at the building.
The source of most of the violence was the mountainous north, where tribal sheiks still resented central government.
First 10 tribal sheiks were taken hostage for a month, then each had to surrender four sons or relatives.
In recent weeks, tribal sheiks have been urging families not to relocate, and some Iraqis who had fled their homes are now returning.
Shortly after that, tribal sheiks began to shout from a few rows back.
The gathering filled a large auditorium, and tribal sheiks in flowing robes could be seen spilling out into hallways.
A number of tribal sheiks have been killed in recent weeks in and around Falluja.
We found a local tribal sheik who said he could corral them.