A pair of mortar rounds slammed into a soccer field while young men were playing a game in a Shiite district of Baghdad on Wednesday as more than 60 people were killed in attacks nationwide.

U.S. forces also said they killed 14 suspected insurgents, detained 48 and rescued a kidnapped Iraqi policeman in a pair of raids outside Baghdad that began Tuesday.

No American casualties were reported in those actions. But the military said separately that a Marine died Wednesday from fighting in the volatile Anbar province west of Baghdad and a U.S. soldier was killed Tuesday in combat around the northern city of Kirkuk.

U.S. ambassador to Iraq, Zalmay Khalilzad, said Wednesday that he did not expect U.S. Iraq policy to change dramatically, despite the election upset. "Americans are prepared to continue to support Iraq as Iraqis take the needed steps," he said in videotaped remarks.

The mortar rounds struck the soccer field in Sadr City as an afternoon game was in progress between young men from the sprawling slum that is home to about 2.5 million people, police Capt. Mohammed Ismail said. At least eight people were killed and 20 wounded, including players and bystanders, he said.

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Dozens of people have been killed in recent days in mortar attacks by rival Sunni and Shiite groups on residential areas in Baghdad.

Two mortar rounds also struck an area in northern Baghdad Wednesday, killing at least one person, police Lt. Mohammed Khayoun said.

Authorities had originally called Tuesday's attack on a coffee shop in another Shiite neighborhood in Baghdad a mortar attack, but Lt. Ali Muhssin said Wednesday that it was a suicide bombing. He also raised the death toll in that attack from 14 to 21, with another 25 wounded.

South of the capital, a bomb planted in a minivan exploded in an open-air market in Mahmoudiyah, killing at least six people and wounding 28, policeman Haider Satar said.

Another 16 people were killed in a string of shootings and bombings in Diyala province north of the capital, while a car bomb in western Baghdad killed three people and wounded three, Lt. Mutaz Salaheddin said.

U.S. forces said they killed 10 suspected insurgents and rescued a kidnapped Iraqi policeman early Wednesday in a raid near Muqdadiyah, 60 miles north of Baghdad.

Acting on a tip, the troops fought their way into a building, where they found the hostage blindfolded and shackled to the floor. The policemen told troops two other patrolmen captured with him days earlier already had been released after their families paid a ransom. A sniper rifle, mortar system, bomb making materials and other weapons were found on the scene, the military said.

U.S. troops also said they killed four suspected insurgents and detained 48 others during a raid on Tuesday afternoon in Ramadi, 70 miles west of Baghdad. Rocket-propelled grenades, machine guns, grenades and explosives-rigged vests used by suicide bombers were found in a vehicle, the military said.

Fighting involving U.S. forces also left nine Iraqi gunmen dead in Kirkuk, 180 miles north of Baghdad, police Brig. Sarhat Abdul-Qadir said, without giving details. The American military had no comment on the report.

In all, at least 66 Iraqi civilians were reported killed or found dead in violence across the country.

In other violence reported by police:

-- A suicide car bomber slammed into a checkpoint on Baghdad's Palestine Street, killing two policemen and wounding two.

-- Gunmen killed at least one man and wounded four in an attack on a Shiite-owened bakery in a predominantly Sunni section of western Baghdad.

-- A car bomb struck near a Sunni mosque in northeastern Baghdad, killing one person and wounding six.

Police also found the bodies of three apparent death squad victims were found dumped on Baghdad streets, a day after the bullet-riddled bodies of 15 victims were found floating in the Tigris River south of the capital. Hundreds of such killings -- in which victims are bound hand and feet, blindfolded, and often tortured -- have been recorded since the bombing of a Shiite shrine in February that ignited successive waves of sectarian killings.

Complete coverage is available in FOXNews.com's Iraq Center.