BAGHDAD — Aides to Muqtada al-Sadr called Monday for dialogue to resolve a violent standoff with the Iraqi government, saying that the radical Shiite cleric would disband his militia if senior religious leaders ordered it.

The overture came as Baghdad's main Shiite district of Sadr City faced continued clashes between al-Sadr's Mahdi Army militia fighters and Iraqi troops backed by U.S. forces.

Also Monday, a U.S. soldier was killed by small-arms fire after a roadside bombing in Baghdad, the military said, pushing the two-day American death toll to at least eight. The attack occurred in an eastern section of the capital which has been the site of the fiercest clashes since al-Sadr ordered a cease-fire a week ago Sunday.

At least nine civilians were killed in fighting Monday in Sadr City, including five children and two women, pushing the two-day death toll to at least 25. Dozens were wounded.

Six others died after rocket or mortar shells slammed into residential areas elsewhere, according to police.

Hundreds of residents fled the district amid the clashes and economic hardship imposed by a security cordon and a vehicle ban.

The surge in violence came on the eve of congressional testimony in Washington by the two top U.S. officials in Iraq — Gen. David Petraeus and Ambassador Ryan Crocker — on the situation in the country and prospects for an eventual withdrawal of American troops.

Al-Sadr plans to hold a "million-strong" anti-U.S. demonstration on Wednesday in Baghdad to protest the fifth anniversary of the capture of the Iraqi capital by invading U.S. troops.

Al-Sadr aide Hassan al-Zarqani said the cleric will consult Grand Ayatollah Ali al-Sistani and other top Shiite clerics in the holy city of Najaf if the government continues to pressure him to disband the militia.

Al-Zarqani said in a telephone interview that al-Sadr "will obey" if al-Sistani, the highest Shiite authority in Iraq, and the other clerics recommend that he do so.

Prime Minister Nouri al-Maliki, in an interview Sunday with CNN, issued his strongest warning yet to al-Sadr to disband his militia or face political isolation.

He said al-Sadr's followers would not be allowed "to participate in the political process or take part in upcoming elections unless they end the Mahdi Army."

He was referring to provincial elections expected in the fall that are likely to redistribute power in Iraq. The Sadrists have accused al-Maliki's government and rival parties of trying to diminish their standing ahead of the vote.

The prime minister, who took office in May 2006 with al-Sadr's support but later broke with the powerful cleric, had in the past repeatedly promised to disband militias. But his comments to CNN were the first time he publicly singled out the Mahdi Army.

"Solving the problem comes in no other way than dissolving the Mahdi Army," al-Maliki said. "We have opened the door for confrontation, a real confrontation with these gangs, and we will not stop until we are in full control of these areas."

Salah al-Obeidi, a spokesman for al-Sadr's office in the holy city of Najaf, said al-Maliki doesn't have the authority to make such a move because the decision is up to Iraq's Electoral High Commission and parliament. He called for dialogue.

"Al-Sadr's office affirms that the door is open to reach an understanding regarding these problems," al-Obeidi told AP Television News.

Senior Sadrist lawmaker Baha al-Aaraji also called for a restructuring of government security institutions, saying any move to disband militias had to be applied to all political parties as well — a reference to the Badr Brigade of the Sadrists' main rival, the Supreme Islamic Iraqi Council, which dominates the Iraqi security forces.

"We say that we are with the law, but it has to be applied to all," al-Aaraji said during a news conference.

U.S. and Iraqi forces continued to clash with Shiite gunmen Monday in Baghdad's militia stronghold of Sadr City, a day after some 1,000 U.S. and Iraqi troops began an offensive to push deeper into the sprawling district.

The inability of the Iraqi forces to curb the militias has cast fresh doubt on their ability to take over their own security on the eve of the Petraeus-Crocker briefings.

The mounting American death toll also was likely to fuel Democratic-led calls to bring troops home more quickly.

In two of the most brazen attacks again U.S. forces on Sunday, suspected Shiite militants lobbed rockets and mortar shells into the U.S.-protected Green Zone and a military base elsewhere in Baghdad, killing three American troops and wounding 31, officials said.

A roadside bomb killed another U.S. soldier Sunday in eastern Baghdad, while two other American soldiers were killed Sunday by a roadside bomb north of the capital in Diyala province, the military said.

Also, a U.S. soldier assigned to the division operating south of Baghdad died of non-combat injuries.

At least 4,021 members of the U.S. military have died since the Iraq war started in March 2003, according to an Associated Press count.

Associated Press writers Hamid Ahmed and Sameer N. Yacoub contributed to this report.