The U.S. military said 14 American troops have died in several attacks in the past 48 hours, including five slain today in a single roadside bombing that also killed four Iraqis in Baghdad.
Elsewhere, a suicide truck bomber struck the Sulaiman Bek city hall in a predominantly Sunni area of northern Iraq, killing at least 16 people and wounding 67, an Iraqi commander said.
The latest U.S. deaths raised to at least 3,545 the number of American troops who have died since the war began in 2003, according to an Associated Press count.
The deadliest attack was a roadside bomb that struck a convoy in northeastern Baghdad today, killing five U.S. soldiers, three Iraqi civilians and one Iraqi interpreter, the military said.
A rocket-propelled grenade struck a vehicle in northern Baghdad about 12:30 p.m. today, killing one soldier and wounding three others, another statement said.
Four other U.S. soldiers were killed and one was wounded Wednesday when their convoy was struck by a roadside bomb in a western neighborhood in the capital, the military said separately.
Southwest of Baghdad, two U.S. soldiers were killed and four were wounded Wednesday when explosions struck near their vehicle, according to a statement earlier in the day.
Two Marines also were killed Wednesday while conducting combat operations in Anbar province, west of Baghdad, the military said.
Several mortars or rockets slammed into the U.S.-controlled Green Zone, raising fresh concerns about the thousands of Americans who live and work in the heavily fortified area in central Baghdad.
The explosion in Sulaiman Bek occurred about 10:30 a.m., and killed 16 people, the local Iraqi army commander said.
Maj. Gen. Anwar Hama Amin, the commander of the Iraqi army's 2nd Brigade, blamed the blast on al-Qaida, saying it was the latest in a series of strikes by the terror network against government officials, whom they accuse of collaborating with the U.S. and the Iraqi government.
Sulaiman Bek is about 100 miles north of the capital and just outside the border with Diyala province, where thousands of U.S. troops are engaged in an offensive against al-Qaida in Iraq.
Amin said the target apparently was the mayor, who has lost five relatives in previous assassination attempts. The blast heavily damaged the city hall, along with several nearby houses and stores.
Thamir Mohammed, a 28-year-old newlywed, said he was on his way to city hall to do some paperwork to get a new ration card when the blast occurred, knocking him off his feet and wounding him in the head and legs.
"I was walking in the street heading to the city hall when a truck drove up and parked outside. The driver got out and was just outside the truck when the explosion took place," Mohammed said from his hospital bed in nearby Tuz Khormato.
It was the latest in a series of attacks as al-Qaida fights back as the U.S. intensifies operations against the terror network in Baghdad and elsewhere around the capital.
A U.S. airstrike aimed at a booby-trapped house in one of the centers of those offensives, the Diyala provincial capital of Baqouba, missed its target and "accidentally hit" another structure, wounding 11 civilians on Wednesday, the military said, adding the incident was under investigation.
U.S. troops had cleared the area to destroy a house containing explosives believed placed by al-Qaida, but "the bomb missed its intended target and struck another structure," the military said. "Reports indicate that 11 civilians were injured."
The initial target was later destroyed by a Hellfire missile, producing a large secondary explosion, according to the statement.
A spokesman for the 1920s Revolution Brigades, a nationalist Sunni insurgent group that has begun cooperating with U.S. and Iraqi forces in the fight against al-Qaida in Diyala, said an airstrike mistakenly struck a building being used as a headquarters by the group. The spokesman, who declined to be identified due to security concerns, said two members were killed and four were wounded.
Maj. Gen. Abdul Karim al-Rubaie of the Iraqi army said the offensive that began Monday in Diyala was going well and operations were focused on the areas of Jurf al-Milih and the northern part of the Baqouba market, which has been the site of several recent execution-style killings by al-Qaida.
Hospital officials said ambulances were bringing dozens of bodies of militants who have been killed from the western half of the city, which was under a strict curfew.
The latest military report on the Diyala offensive said U.S.-led forces had killed 41 insurgents, discovered five weapons caches and destroyed 25 bombs and five booby-trapped houses.
The U.S. military said it has 10,000 American soldiers in Diyala province, an al-Qaida bastion, a troop strength that matched in size the force that American generals sent against the insurgent-held city of Fallujah 21/2 years ago.
With all of the nearly 30,000 additional troops ordered to Iraq by President Bush now in place, the military said the massive operations on Baghdad's flanks were "a powerful crackdown to defeat extremists" and named the combined offensives "Operation Phantom Thunder."
Violence persisted in Baghdad, with a series of mortars or rockets slammed into the U.S.-controlled Green Zone, which houses the U.S. and British embassies and major Iraqi government headquarters.
A huge plume of black smoke rose from the sprawling complex on the west bank of the Tigris River and helicopters buzzed overhead after about nine blasts occurred in quick succession around 10 a.m.
At least one mortar round struck a parking lot used by Prime Minister Nouri al-Maliki and his security detail, an official from his office said, speaking on condition of anonymity because he wasn't authorized to release the information.
The U.S. Embassy confirmed rounds of indirect fire, the military term for rockets or mortars, but said it did not have information about casualties.
Elsewhere, sports officials gathered for a funeral for an Iraqi bodybuilding champion, Mahir Mohammed Ali, who was killed in the bombing of a Shiite mosque Tuesday in central Baghdad.
The director of a branch office of radical Shiite cleric Muqtada al-Sadr near the southern city of Hillah also was killed in a drive-by shooting, police said, declining to be identified due to security concerns.
Mortar rounds also struck a residential area in a Shiite enclave in Baghdad's southern Dora neighborhood, killing one civilian and wounding four others, police said.
Associated Press writers Bushra Juhi and Qassim Abdul-Zahra contributed to this report in Baghdad.
14 U.S. troops killed in 48 hours