In the northern city of Mosul, another vehicle bomb went off, wounding four Americans.
Also in Mosul, three decapitated bodies — two Iraqis and an unidentified corpse — have been found in and around the city, a coroner said, the latest in a grisly campaign of beheadings by militants who have been snatching foreigners and Iraqis accused of helping the United States.
U.S. warplanes pounded the vast Baghdad slum of Sadr City overnight after an American patrol came under gunfire, the military said Tuesday. Hospital officials said at least one Iraqi was killed in the violence in the district, a stronghold for Shiite militiamen.
Near Baghdad, one soldier was killed Monday night and two were injured when their convoy hit a homemade bomb, the military said. As of Monday, 1,055 U.S. troops have died in Iraq.
In other developments:
Ramadi, 70 miles west of Baghdad, is one of the Sunni Triangle cities where U.S. and Iraqi commanders are considering launching a new push to clear out insurgents ahead of key January elections.
Intensifying violence — including near-daily car bombs and persistent abductions — and the insurgents' dominance in several cities have raised concerns over the vote. Iraqi and U.S. leaders insist they will be held on schedule, though some officials have said voting may not be possible in the most violence-torn areas, which are largely Sunni Muslim.
A powerful group of Sunni Muslim clerics on Tuesday warned against leaving out parts of the country, saying it would undermine the vote and be tantamount to fragmenting Iraq.
"This could be a bad omen for the unity of the country because this means that (the excluded areas) would be separated from the rest of Iraq," said Mohammed Bashar al-Faidhi, a spokesman for the Association of Muslim Clerics.
In Ramadi on Tuesday, a booby-trapped car exploded near the city's Grand Mosque as a U.S. military convoy passed. Four Iraqis inside a car near the explosion were killed and two bystanders were wounded, said Dr. Dia'a al-Haity, a doctor at Ramadi General Hospital.
Witnesses said a wounded U.S. soldier was seen being carried away by his colleagues after the blast, which punched a crater into the ground and mangled a nearby vehicle. The U.S. military said it had no information on the incident.
Earlier Tuesday, another car bomb exploded in another part of the city, sparking a gunbattle between U.S. forces and gunmen. Al-Haiti said two Iraqis were killed and four wounded in the fighting.
Mosul, 225 miles northwest of Baghdad, has seen increased rebel attacks in recent weeks, with frequent car bombings. Previously, the city and its surroundings were among the more peaceful regions in the country.
A car bomb in the city Tuesday targeted a U.S. convoy, wounding four American soldiers, the U.S. military said.
U.S. troops opened fire after the explosion, killing three Iraqis in a passing vehicle and wounding a number of others, said police 2nd Lt. Mohammed Ahmed.
Rebels opened fire on a group of policemen as they were returning to Baghdad from Mahmoudiyah, 20 miles south of the capital Monday, said Brig. Ali al-Musaw. Lt. Col. Abdul-Latif Metasher Nejm was killed along with a major and five other policemen, he said.
In Latifiyah, five miles further south, three policemen were shot dead Monday as they stopped at a gas station, said policeman Faez Nasser.
There was one survivor who told authorities the assailants took $1 million from their vehicle, Nasser said. It was not clear why the police had this amount of money in their possession.
Mohamed Qadir Youssef, a worker at the al-Jomhuria Hospital, said three people were killed and three others wounded.
Hospital officials in Sadr City said Tuesday that at least one person was killed in skirmishes overnight. Residents said they continued to hear loud explosions until dawn.
Bremer's comments raised eyebrows because they are similar in tone to criticism by Democratic presidential nominee Sen. John Kerry and others.
"We paid a big price for not stopping it because it established an atmosphere of lawlessness," Bremer told an insurance group in White Sulphur Springs, W.Va. The group released a summary of his remarks in Washington.
"We never had enough troops on the ground," Bremer said. But he insisted he was "more convinced than ever that regime change was the right thing to do."