Four U.S. soldiers died Monday from wounds suffered in a combat explosion in Diyala province north of Baghdad, the American military reported. Twelve others had minor injuries and returned to duty.
The military statement announcing the deaths gave no other details and said identities of the victims were being withheld until family could be notified.
Earlier Monday the military said one soldier was killed during fighting in eastern Baghdad a day earlier. Two soldiers were wounded in the fighting.
At least 3,673 members of the U.S. military have died since the Iraq war started in March 2003, according to an Associated Press count.
Meanwhile, a suicide bomber slammed his truck into a densely populated residential area in the northern Iraqi city of Tal Afar on Monday, killing at least 28 people, police said. The attack occurred in a crowded Shiite neighborhood of the mixed city, 260 miles northwest of Baghdad.
At least 40 others were wounded in the attack, said Brig. Gen. Rahim al-Jibouri, commander of Tal Afar police. The death toll was expected to rise, he said.
Meanwhile in Baghdad, a roadside bomb killed nine civilians and wounded eight during rush hour Monday morning, police said.
The bomb had been planted at the Zaafaraniyah intersection in the Jisr Diyala area, a predominantly Shiite neighborhood, an officer said on condition of anonymity because he was not authorized to speak to media. The route is frequently used by Iraqi police and army patrols. All the victims were pedestrians, the officer said. Three cars were also damaged.
The attacker in Tal Afar drove a dump truck filled with explosives and covered with a layer of gravel, said Brig. Najim Abdullah.
Within an hour of the attack, authorities imposed a complete curfew on the city, he said.
Abdullah, who also is mayor of Tal Afar, said the blast occurred six miles northeast of the city center. Most of the dead, he said, were women and children. Rescue workers were still digging in the rubble for more victims.
In other developments:
Many of them stemmed from allegations by a 50-year-old Sunni Arab woman, who came forward last February and said Iraqi soldiers raped her when they raided her house searching for weapons. Sunni insurgents have kidnapped and killed dozens of Iraqi security officials in response.
The city also recorded one of the deadliest days since the start of the Iraq war, when at least 152 people died in truck bombings on March 27, 2007.
In recent weeks, some U.S. military commanders have said additional troops will be needed into 2008, and suggested that a verdict on President Bush's current troop increase be delayed until November.
But many Democrats and some Republicans in Congress have made clear a desire for a fundamental shift in war policy, should the September assessments fail to show clear progress.
Sen. Mitch McConnell, the Senate Republican leader, also has dismissed any suggestion of waiting beyond September for a verdict on Mr. Bush's war policy.
On Sunday, Secretary of Defense Robert Gates said he still expected the Bush administration to make a "strategic reassessment" in September on U.S. involvement in the four-year war.
Gates — a member of the bipartisan Iraq Study Group until he was nominated as defense secretary last November — also acknowledged he probably would have sided with other members of the study group in urging the U.S. to reduce its military involvement should there be too few political gains in Iraq.
But, he's said since then that the U.S. has had unexpected, good progress on the local level in Iraq.
"Circumstances changed in a different way," Gates said. "That's the process we hope will evolve over time."
Secretary of State Condoleezza Rice agreed.
Security "has improved some" because of U.S. and Iraqi cooperation, she said Sunday. Military commanders have attributed the decline in violence in Anbar province to their efforts to work with local tribal leaders who grew sick of insurgency-spawned bloodshed and turned their backs on al Qaeda.
"Clearly, too, we have a lot of work to do on the political side," she said. But, she added, "I would not underestimate the importance of the continuing work of the leaders of these very powerful parties in Iraq."
Rice said that violence attributed to "large-scale sectarian death squads" has diminished in Iraq, but al Qaeda-inspired violence still "can get off the big car bomb" that kills civilians.
She said the Iraqi parliament probably could have passed a national oil reconciliation law with just a simple majority vote, but instead the lawmakers had wanted to reach a real consensus, which "makes a lot of sense."
A majority vote would get the law passed "but it would not have the force of all of the groups that wanted to do this," she said. "They don't want a 51-49 on constitutional reform."
Gates appeared on NBC television's "Meet the Press" and CNN's "Late Edition," while Rice spoke on "Fox News Sunday" and CBS' Face the Nation.