The soldiers in the northern city of Rabia, 90 miles west of the larger city of Mosul, were armed and dressed in street clothes, confusing police, said the region's police chief, Ahmed Mohammed Khalaf. Three soldiers and two police were killed, while eight were wounded in the 10-minute exchange of friendly fire.
In the former rebel stronghold of Fallujah, police patrolled the streets and imposed a sudden, late-afternoon curfew, shouting through loudspeakers: "Close your stores and go home!" They also set up checkpoints and searched cars in the city.
It was not known why the sudden curfew was put in place. Earlier, a battle broke out in the northern Jolan neighborhood between unidentified gunmen and Iraqi security forces, witnesses said. "We were surprised to see a large number of Iraqi security forces raiding homes and dragging out young men, maybe for investigations," resident Jamal Mohammed said.
In other developments:
In Baghdad, hundreds of electricity workers saying they were fed up with sometimes deadly insurgent attacks against Iraq's power sector marched through the streets shouting "No, no to terror!"
Insurgents have targeted the power grid in their two-year campaign to undermine the U.S.-led coalition and emerging Iraqi government, sometimes killing workers in attacks against power stations and pipelines.
And in the southern city of Basra, more than 200 protesters demanded an individual from their petroleum-rich region be named head of the oil ministry. Some demonstrators even threatened to strike if their demands weren't met.
"Everyone must know that the oppressed and persecuted people of the south refuse to have their interests be ignored," protesters said in a statement given to the provincial governor, Mohammed al-Waeli.
Al-Waeli agreed, saying: "We are eager that the people of Basra and the south have clout in the new government."
As Iraq's postelection political process unfurls, the top U.N. envoy in Iraq, Ashraf Qazi, sat down with the Association of Muslim Scholars, a group of leading Sunni religious leaders, Thursday in a Baghdad mosque.
Qazi "stressed the importance of ensuring that all components of Iraqi society are adequately represented in the constitutional making process," a U.N. statement said.
Shiite Muslim and ethnic Kurdish officials also met Thursday to negotiate details of the country's new government. Jawad al-Maliki, a negotiator from the United Iraqi Alliance, which won the most votes in the Jan. 30 elections, said the two groups agreed to hold parliament's next session early next week. No firm date has been set.
"The negotiations were positive and very good," al-Maliki said. "In the coming days, the meetings will be continuous and decisive."
Negotiators are considering the involvement of the Sunnis beyond even just the eventual writing of Iraq's constitution.
The Sunnis, from whose ranks many insurgent fighters are believed drawn, largely stayed away from Iraq's historic vote. Kurdish and Shiite negotiators say they're discussing handing a Sunni Arab the defense minister's post in an effort to include them in the process.
Kurds are thought to number between 15 percent to 20 percent of Iraq's 26 million people, with Sunni Arabs roughly equivalent. Shiite Arabs make up 60 percent of the population.
Insurgents kept up their campaign of attacks Thursday, targeting Americans with roadside bombs in the north and attacking Iraq's nascent army in the capital.
Two separate explosives planted in the streets of Mosul detonated near U.S. patrols, according to witnesses, who said they didn't believe there were any casualties.
One blast near a Mosul school caused panicked children to pile out of the building before lessons were canceled for the day, said Khairy Ilham, a shopkeeper who witnessed the blast. The U.S. military wasn't immediately available for comment.
In Baghdad, gunmen opened fire on a two-ton army truck transporting soldiers in an eastern neighborhood. The truck overturned, injuring 12 troop members, police Maj. Mousa Hussein said.