The aide, Hazem al-Araji, was arrested by U.S. troops while attending a meeting of tribal leaders at a Baghdad hotel.
The arrest came as al-Sadr appeared to be on the retreat, ordering members of his Al-Mahdi Army to leave police stations and government buildings in Al-Najaf, Karbala, and Kufa.
A delegation of Shi'ite clerics is reportedly holding talks with al-Sadr in the hope of resolving the standoff between the U.S. military and the cleric, who over the past week has called for a bloody uprising against the coalition.
The U.S. military says its mission remains to "kill or capture" al-Sadr.
West of Baghdad, an informal cease-fire is reportedly holding on the U.S.-led coalition's second front, in the Sunni flashpoint town of Al-Fallujah.
The arrest came as al-Sadr appeared to be on the retreat, ordering members of his Al-Mahdi Army to leave police stations and government buildings in Al-Najaf, Karbala, and Kufa.
A delegation of Shi'ite clerics is reportedly holding talks with al-Sadr in the hope of resolving the standoff between the U.S. military and the cleric, who over the past week has called for a bloody uprising against the coalition.
The U.S. military says its mission remains to "kill or capture" al-Sadr.
West of Baghdad, an informal cease-fire is reportedly holding on the U.S.-led coalition's second front, in the Sunni flashpoint town of Al-Fallujah.
