The Americans were wounded in separate attacks in northern Iraq. One car bombing and ambush wounded eight soldiers, prompting an American warplane to drop a 500-pound bomb on an insurgent position in Mosul.
Violence continues to grip the Sunni-dominated areas in central Iraq, despite last month's U.S.-led assault on the main insurgent stronghold of Fallujah and on an area south of Baghdad. That attack was launched to try to curb the insurgency so parliamentary elections could be held nationwide Jan. 30.
The latest attacks appear to be part of a sweeping intimidation campaign aimed at foiling those elections, in part by killing Iraqis who cooperate with the United States, making them collaborators in the eyes of insurgents.
Also Saturday, a military spokesman said U.S. commanders welcomed news that the Pentagon intended to.
The issue of whether the military was providing enough protection for its troops received new attention this week after an Iraq-bound National Guardsman questioned Defense Secretary Donald H. Rumsfeld in neighboring Kuwait on why he and his comrades must comb through scrap piles for metal to protect their vehicles.
"Commanders are looking for any opportunity to increase force protection for the sake of their troops," said Maj. Neal O'Brien, spokesman for the Tikrit-based 1st Infantry Division. "Uparmor or add-on armor will always be one of those force protection assets they want more of."
In other developments:
The guerrillas regard the elections as an effort to legitimize a puppet government that will serve U.S. interests.
Iraq's government says the vote will go ahead as scheduled, and preparations continued Saturday, with election officials saying candidates from 70 political parties and coalitions have filed so far. The filing deadline is Dec. 15.
Police Col. Najeeb al-Joubouri was gunned down on his way to work on a road outside Beiji, 155 miles north of Baghdad.
Two more police commanders were shot and killed in Baghdad's southwestern Saidiyah neighborhood in an early-morning ambush. A senior Interior Ministry official identified the victims as Brig. Gen. Razzaq Karim Mahmood and Col. Karim Farhan.
Gunmen ambushed a police patrol in Baghdad's northern suburb of Azamiyah late Friday, killing a captain and a constable and wounding two others, police Lt. Mohammed al-Obeidi said.
In other violence, gunmen shot and killed a Shiite cleric, Salim al-Yaqoubi, near his home in Baghdad, police said.
A second Shiite cleric, Sheik Ammar al-Joubouri, was slain Friday near Mahmoudiya, about 25 miles south of Baghdad, while driving to the capital. Al-Joubouri once headed a religious court of followers of anti-U.S. cleric Muqtada al-Sadr in the southern holy city of Najaf.
In northern Iraq, a suspected suicide car bomber wounded two U.S. soldiers in Beiji, while two more were wounded in a car bomb blast near Kirkuk, about 60 miles to the north.
Two more U.S. soldiers were wounded by a roadside bomb outside Hawija, near Kirkuk.
Separately, police on Saturday found seven bodies apparently killed several days ago and dumped near a highway about 20 miles west of Ramadi.
Lt. Col. Ziyad al-Jubouri said the seven were dark-skinned and didn't look Iraqi, while a hospital official said two Sudanese men asked about the bodies at the morgue. The Sudanese Embassy said it has heard of the grisly finds and sent an official to investigate.
In the central Iraqi city of Samarra, a mortar shell slammed into a car, killing one occupant and injuring another, U.S. military spokesman Master Sgt. Robert Powell said. The attack happened late Friday near a river ferry terminal and a mile from a U.S. military base.