Sadr's Militia and the Slaughter in the Streets

Lawson and Wayman offered several examples. One was a female worker at a Sadr City clinic that Mahdi Army members believed was a brothel. The militiamen warned the women there to shut the place down, pistol-whipped them in public and then shot the worker dead on the street, the two Americans said.

In another case, Lawson spotted the unmoving form of a paunchy man in a checked shirt by the side of the road. Residents told Lawson that the man, a Sunni, had been taken from his home in Mansour, an affluent neighborhood of Sunnis, Shiites and Christians in central Baghdad. Accused of conspiring to drive Shiites from their homes, the Sunni man had been brought to Sadr City and shot dead where he now lay, witnesses told the Americans.

In late spring, Wayman recalled, the Americans in Sadr City happened upon uniformed Iraqi security forces clustered around the body of an Iraqi man. Gunmen had shot the man dead seconds before, then sped off when the Iraqi and U.S. forces happened by, Wayman said.

Americans traced the killers' vehicle to a nearby police station, where they found two grateful captives inside. The men were Christians who told Wayman they worked at a store elsewhere in Baghdad that sold alcohol. Gunmen had visited the shop to tell the men that alcohol was forbidden by the Koran and that they must shut down. When the two refused, they told Wayman, the gunmen stuffed them into a car at gunpoint and brought them to a house in Sadr City.

A Shiite cleric visited the two Christians at the house, they told Wayman. The cleric demanded that the captives convert to Islam and, when they refused, informed them that alcohol was forbidden by Islam.

They would be punished, the cleric said, but he did not specify how. The captives said they believed they were second and third in line for execution, after the man who was found in the street.

Mahdi Army commanders interviewed uniformly denied that they kill people for selling alcohol. The Mahdi Army only warns liquor vendors, increasingly strongly, they said. If the vendors still refuse to stop selling, the Mahdi Army "beats them lightly, in accordance with the Koran," the commander known as the Sheik said.

Lawson, the intelligence officer, credits the Mahdi Army with an intelligence operation that has become skilled at feeding bad information to Americans about the militia's activities. But U.S. military officials say they know enough to condemn much of what the Mahdi Army does.

"I have no doubt . . . they hold trial courts and execute people," said Lt. Col. Mark Meadows, commander of a cavalry regiment with the U.S. Army's 10th Mountain Division. Meadows's men oversaw Shula, a northern Baghdad neighborhood under Sadr's control, at the time of the Samarra bombing. The Mahdi Army "is probably the largest, most aggressive militia in this country," Meadows said. "They are a terrorist organization. They terrorize people."

But Iraqi and U.S. security forces are often left as puzzled spectators in areas under the Mahdi Army's jurisdiction.

On patrol early one morning, Wayman and his convoy pulled over at the telltale sign of a group of Iraqi police gathered by the side of a road in northern Sadr City, eyes cast down.

The police officers made room for Wayman, who looked down at an Iraqi girl lying on her side. She appeared to be no more than 15. The morning light bathed her face, and her hands curled gently to her mouth. Wrapped in a blanket, she looked asleep, except for two bursts of pink flesh from bullet wounds in her back.

Neither American nor Iraqi forces had any inclination to investigate what had happened to the teenager.

"Who knows?" one of the Iraqi policeman said, preparing to bundle up the body. Wayman got back into his Humvee, and the Americans drove on.