The New York Time BAGHDAD — The long lines of Shiite fighters began marching through the capital early Saturday morning. Some wore masks. One group had yellow and green suicide 
explosives, which they said were live, strapped to their chests.
As their numbers grew, they swelled into a seemingly unending procession of volunteers with rifles, machine guns and rocket-propelled grenades, backed by mortar crews and gun and rocket trucks.
The Mahdi Army, the paramilitary force that once led a Shiite rebellion against American troops here, was making its largest show of force since it suspended fighting in 2008. This time, its fighters were raising arms against the Islamic State in Iraq and Syria, or ISIS, the Qaeda splinter group that has driven Iraq’s security forces from parts of the country’s north and west.
Chanting “One, two, three, Mahdi!” they implored their leader, the cleric Moktada al-Sadr, to send them to battle.