BAGHDAD, Iraq -- Bombs, rockets, mortar shells and gunfire claimed the lives of at least 70 Iraqis and injured hundreds Sunday, as top Iraqi politicians vowed to redouble efforts to form a national-unity government to help ease a recent surge in sectarian violence.

The most deadly violence of the day involved apparently coordinated attacks on Sadr City, the sprawling Shiite Muslim area in eastern Baghdad, that left at least 46 people dead and more than 200 wounded.

Sheik Hassan al-Rubaie, an aide to radical cleric Muqtada al-Sadr, said Sadr City Hospital was overflowing with wounded patients and the bodies of the dead.

Gunmen and explosions killed 12 Iraqis elsewhere in the capital, while the bodies of a dozen others were found around the city, some in a sewage ditch, according to police and hospital officials.

Iraqi political leaders, meanwhile, agreed to expedite negotiations on forming a new national-unity government that would include all the main political parties. Negotiations stalled in the sectarian violence that erupted after the Samarra mosque bombing last month and then stalemated when Kurds and Sunnis demanded that the Shiites withdraw their nominee for prime minister, Ibrahim al-Jaafari, saying he had not done enough to improve security or advance reconstruction during his year as transitional prime minister.

Al-Jaafari, who was nominated with al-Sadr's strong backing, has refused to withdraw, saying he was legitimately nominated by the United Iraqi Alliance, a 130-member Shiite coalition that has the largest bloc in Iraq's 275-member parliament.

President Jalal Talabani, a Kurd, and Abdul Aziz al-Hakim, an influential Shiite leader, said top leaders from every faction had agreed to begin daily negotiations.

In a sign of the urgency of the matter, and to avoid conflicts with a Shiite holiday, the parties agreed to move up the opening day of parliament by three days to Thursday. It was previously scheduled for next Sunday.

U.S. Ambassador Zalmay Khalilzad has urged the parties to expedite the formation of a coalition government to help stanch sectarian bloodshed.

"The situation is such that there is a degree of vacuum in authority in the current caretaker government," Khalilzad said. "There is continuous effort by the terrorists to promote sectarian conflict, and therefore in order to deal with the threat, there is a need on an urgent basis to form a government of national unity."

The political development came as Iraq's defense and interior ministers announced that their agencies would begin conducting security raids jointly to raise public confidence that the Shiite-led Interior Ministry was not harboring death squads that target Sunni Arabs and their mosques, as Sunni leaders have alleged.

Interior Minister Bayan Jabr, a Shiite, and Defense Minister Sadoun al-Dulaimi, a Sunni, unveiled a new policy requiring that all suspects arrested by security forces be presented in court within three days.

On the streets of Baghdad, meanwhile, killings continued.

The violence began at dawn, when a roadside bomb exploded near an Iraqi army patrol in the Mustensiriya neighborhood, critically injuring five soldiers. An hour later, a mortar hit a house in the center of the capital, killing two people and wounding six. Other attacks followed, including a roadside bomb that exploded near a U.S. convoy, killing six Iraqis and injuring 13.

At noon, gunmen shot to death two electrical engineers in central Baghdad. A few hours later, assassins killed an Iraqi actor on the southern edge of the capital and assailants killed a Ministry of Defense translator as he was driving near the city center.

The bound and blindfolded bodies of eight men were found in a sewage ditch in Rustimiya, southeast of Baghdad. Each had been shot in the head. The bodies of three men were found inside a parked car in the industrial area of Bayaa. Another body, showing evidence of torture, was found under a bridge in the city center.

Close to sunset, car bombs, one detonated by a suicide attacker, tore through two busy markets in Sadr City.

Seattle Times news services

Information from The Washington Post, Los Angeles Times, Chicago Tribune and The Associated Press is included in this report.