http://www.mercurynews.com/mld/mercurynews/news/special_packages/iraq/15032026.htmBAGHDAD, Iraq - As a car enters the Shiite district of Sadr City, a group of men step from the curb and flag down the vehicle. "Who are you and where are you going?" one of them demands.
All is well after passengers produce papers, not from the government but from the office of radical Shiite cleric Muqtada al-Sadr. "We are sorry," one man says. "May God be with you."
Al-Sadr's militia, the Mahdi Army, keeps a sharp eye out for strangers in the teeming Baghdad district, home to 2.5 million people, as well as other Shiite areas across the country.
By day, militiamen in Sadr City keep weapons out of sight. By night, they set up checkpoints, where they search cars and examine IDs to guard against would-be suicide bombers and other Sunni Arab militants.