Elsewhere, insurgents fired mortars at the provincial administration offices in the northern city of Mosul, wounding four of the governor's guards, the U.S. military said
Governor Duraid Kashmoula was unhurt in the attack, said spokesman Lt. Col. Paul Hastings. Initial reports said the mortar attack landed near a fuel truck, setting it ablaze, Hastings said.
The rest of Mosul, Iraq's third largest with more than a million residents, remained calm for a second day since the U.S.-led offensive operation began on Tuesday to wrest control of the western part of the city from insurgents.
Last week, gunmen stormed police stations, bridges and political offices, overwhelming police forces who, in many places, failed to even put up a fight. Some officers also allegedly cooperated with insurgents.
The U.S. military said that up to 2,500 U.S. and Iraqi troops met "little resistance" during operations to re-secure police stations and key bridges in Mosul from the insurgents.
Thursday's attacks came a day after a wave of violence in Iraq's Sunni Muslim heartland killed at least 27 people and U.S. forces pursued the remaining holdouts in the former insurgent bastion of Fallujah.
In other developments:
While U.S. and Iraqi forces have retaken insurgent strongholds in Fallujah and Mosul, violence continues to erupt in Sunni Muslim-dominated areas of Iraq.
Condemnation of the apparent killing of kidnapped British aid worker Margaret Hassan continued to be heard.
Australian Prime Minister John Howard said Thursday a body found in the strife-torn Iraqi city of Fallujah was likely that of Hassan -- repeating the belief of British officials and Hassan's family.
"The body found in Fallujah appears to have been Margaret's and the video of the execution of a Western woman appears on all the available information to have been genuine," Howard told Parliament.
Howard did not say which body he was referring to but on Sunday, Marines found the mutilated body of what they believe was a Western woman on a street in Fallujah during the U.S. assault on the insurgent stronghold.
Hassan, 59, director of CARE International's operations in Iraq, was a British citizen born in Ireland and married to an Iraqi man.
The body, clothed in what appeared to be a purple, velour dress, was wrapped in a blanket, with a blood-soaked black cloth nearby. As of Thursday, the U.S. command said the body had not been identified.
When questioned outside Parliament about his comments, Howard did not confirm which body he was talking about and said no remains had been yet returned to authorities.
"This latest example of cruelty and brutality reminds us that there can be only one answer to terrorism and that is the completely uncompromising and unconditional one," he said.
The Arab satellite station Al-Jazeera said early this week it had received a videotape showing the murder of a woman believed to be Hassan, a British-Irish national who had lived in Iraq for three decades.