As suicide bombers kept up their campaign for a second day, at least 31 people were killed — 23 of them Iraqi police and Interior Ministry commandos, now targets of choice for the Sunni-dominated insurgency.
At least seven of 570 people wounded in Wednesday's attacks have died, hospital officials said, raising the toll to at least 167 in the worst day of killing to hit the capital since the U.S.-led invasion in March 2003.
"These spikes of violence are predictable around certain critical events that highlight the progress of democracy," said Maj. Gen. Rick Lynch, the chief American military spokesman.
"Remember, democracy equals failure for the insurgency. So there has to be heightened awareness now as we work our way toward the referendum" on Oct. 15, he said. "That's power, that's movement toward democracy."
In other developments:
Al Qaeda in Iraq, headed by Jordanian terrorist Abu Musab al-Zarqawi, claimed responsibility for the bombing campaign launched after an Iraqi-U.S. force of 8,500 stormed the northern city of Tal Afar, an insurgent bastion, this week.
Al-Zarqawi purportedly declared "all-out war" on Shiite Muslims, Iraqi troops and the government in what the United States has called a desperate propaganda campaign to derail the political process.
Leaders of the Sunni Arab minority in Iraq have vowed to defeat the constitution, which they claim favors the Shiite majority and the Kurds.
Lynch said the joint force killed 145 insurgents and captured 361 in the second operation in a year to rid Tal Afar of militants, including foreign fighters crossing from Syria.
Now, he said, U.S. forces along with the Iraqis were fighting to regain control of the Syrian border, near the western insurgent stronghold of Qaim well to the south of Tal Afar.
"The focus is ... to restore control of the border and in this particular case the border with Syria," he said. "We believe that the terrorists and foreign fighters are entering Iraq across the Syrian border, down the Euphrates River Valley into Baghdad."
Recent violence only served to deepen the misery in Baghdad, where streets were noticeably quieter Thursday — deserted in the southern Dora district where the latest bombings were concentrated.
U.S. and Iraqi forces using loudspeakers roamed the district warning residents to stay indoors because five more suicide car bombers were believed to be in the area.