U.S. Role Deepens in Sadr City

Falah Hassan Shanshal, a Sadrist member of parliament, said at least five houses were demolished in the airstrike, killing 29 people and pinning entire families beneath piles of rubble. When a bulldozer came to clear the rubble, the driver was shot by a sniper, Shanshal said.

An Associated Press photograph showed a boy being pulled from the rubble. The AP reported that Ali Hussein, 2, died at the hospital.

"Sadr City is under the American hammer and nobody is monitoring it," said Leewa Smeisim, the head of the Sadr movement's political bureau. "Eighty percent of the military operations are targeting innocents, because the Americans want to make people turn against the Mahdi Army so they can enter the city and control it. Nobody is safe in Sadr City, neither women nor children."

U.S. officials emphasized that U.S. troops responded only after they were attacked and that it was the fault of the militiamen if there were civilian casualties. "The sole burden of responsibility lies on the shoulders of the militants who care nothing for the Iraqi people," Stover said in an e-mail.

He said the militiamen purposely attack from buildings and alleyways in densely populated areas, hoping to protect themselves by hiding among civilians. "What does that say about the enemy?" Stover said. "He is heartless and evil."

The protracted clashes in Sadr City appear to be the unintended consequence of the offensive that Maliki launched in Basra without consulting U.S. officials. Shiite fighters in Sadr City retaliated by pummeling the heavily fortified Green Zone, the center of the Iraqi government and the U.S. mission here. U.S. forces then mobilized to support the Iraqi effort and protect the Green Zone from attacks.

Now, U.S. and Iraqi troops are fighting together to clear the southern portion of Sadr City, where militia fighters have launched their rocket and mortar attacks.

Three more rockets struck the Green Zone on Tuesday, killing at least one Iraqi, according to a U.S. military official who spoke on the condition of anonymity. Baghdad was engulfed for much of the day by the yellowish haze of a dust storm, making it difficult for U.S. drones and other aircraft to spot militiamen firing rockets and mortars.

Elsewhere in the capital, Tariq Aziz, who for years was the public face of Saddam Hussein's government, went on trial facing charges of ordering the execution of dozens of Iraqi merchants allegedly involved in profiteering. Aziz, 72, who served as foreign minister and deputy prime minister, faces the death penalty if convicted. The trial was postponed until May 20 because one of his co-defendants is ill and could not attend the hearing.

In volatile Diyala province, a Sunni stronghold northeast of the capital, a female suicide bomber attacked in the village of Mukhisa, killing at least one person and wounding five, police said. The victims were all members of the Awakening movement, mainly Sunni tribesmen who have joined with U.S. forces to fight against the Sunni insurgent group al-Qaeda in Iraq.

But much of the country remained worried about the fighting in Sadr City and whether it would spark a full-scale uprising by the Sadrist movement.

Sadr has threatened to call off the eight-month cease-fire, which has been widely credited with lowering the level of violence in Iraq, if the government does not end its offensive against his followers.

Ali al-Dabbagh, the Iraqi government spokesman, did not respond to repeated calls for comment. Followers of Sadr, however, said they were growing more eager for an all-out war to defend themselves.

"We are very close to the Zero Hour," said Ala'a Abd, 30, a Mahdi Army member in the Shiite holy city of Najaf, using an Arabic expression meaning that time is up. "Everyone should realize that."

Special correspondents Saad Sarhan in Najaf, Aahad Ali in Basra and Zaid Sabah in Baghdad and other Washington Post staff in Iraq contributed to this report.