Baghdad ? Anti-U.S. Shiite leader Muqtada al-Sadr ordered most of his militiamen Friday to lay down their arms, and his spokesman said the young cleric might call off all resistance if the Americans accept a timetable to leave Iraq.

Moves toward peace from al-Sadr and the bloody attack in Tal Afar, a predominantly Turkoman city with a small Arab community, underscore the complexity of trying to ensure stability here despite a dramatic improvement in security nationwide.

The order from al-Sadr, who mounted two uprisings against U.S.-led forces in 2004, was read to his followers during weekly Friday prayers in Shiite mosques across the country. He instructed his Mahdi Army militiamen to join religious and social welfare classes as part of a new organization – the “Momahidoun,” or “those who pave the way.”

Posters announcing the Momahidoun have appeared on walls in Sadr City, the cleric’s Baghdad base and home to an estimated 2.5 million Shiites.

“It is an ideological, cultural, religious and social army that will be charged with carrying out an intellectual and scientific holy war and to free the minds, hearts and souls from the secularist Western onslaught and is absolutely prohibited from the use of arms,” the posters say.

Al-Sadr has been moving toward a primarily political role for his militia since August 2007, when he declared a unilateral cease-fire.