The fighting is part of a 5-week-old crackdown by the Iraqi government and U.S. forces on Shiite militia factions. The clashes have brought deep rifts among Iraq's Shiite majority and have pulled U.S. troops into difficult urban combat.

Militia members have been blamed for firing hundreds of rockets or mortars from Sadr City into the Green Zone, the U.S.-protected area housing the American embassy and much of the Iraqi government. In the past month, more than a dozen people — including two American civilians and two U.S. soldiers — have been killed inside the zone during the attacks.

In response to the shelling, American and Iraqi troops in recent weeks have moved into Sadr City, hoping to push the militants far enough from the Green Zone so their rockets and mortars would be out of range.

Iraq's Prime Minister Nouri al-Maliki, a Shiite, shows no indication of easing the pressure on militia groups, including the powerful Mahdi Army led by al-Sadr. Al-Maliki has been seeking to increase leverage on Iran, which is accused of training and arming some Shiite militia groups. Iran denies the claims.

A five-member Iraqi delegation returned from Tehran Saturday from a meeting aimed at halting suspected Iranian aid to militiamen.

Ranking deputy Khalid al-Atiyah said the Iranian government had expressed its readiness to assist the Iraqi government" against the extremists and "in its security measures." He did not elaborate.

During clashes over the past two days in Sadr City, at least 100 people have been killed, Iraqi health officials said.

Also Saturday, the Turkish military claimed air strikes it carried out earlier this week in northern Iraq killed more than 150 Kurdish rebels. The military said it successfully hit all its targets in a three-hour air operation on Mount Qandil early Friday.

The leadership of the Kurdish rebel group is believed to be hiding in the Qandil region — about 60 miles from the Turkish border.

In northern Iraq, Ahmed Danaf, the head of external relations for Kurdish group, claimed in a phone call that the raid killed six members of the Free Life Party, the anti-Iran Kurdish group PEJAK.

The U.S. military also said Saturday that a U.S. soldier died of wounds suffered in a roadside bomb that struck the soldier's vehicle during a combat patrol in eastern Baghdad the day before.

Georgian Defense Ministry spokesman Giga Tatishvili said two servicemen from the ex-Soviet republic were killed and one wounded south of Baghdad on Friday when a parked car bomb exploded. The deaths were the first combat fatalities the nation's military has suffered in Iraq, where it has had a presence since August 2003.