BAGHDAD, Iraq -- Iraq's prime minister tightened an already severe security clampdown in the capital yesterday in an attempt to restore order on downtown streets during an hours-long gunbattle that at times involved Iraqi and American troops fighting Shiite and Sunni Arab gunmen.
With Baghdad residents already facing a midday vehicle ban yesterday, Prime Minister Nouri al-Maliki declared a state of emergency and ordered all residents off the streets until 6 a.m. today.
Frightened residents found themselves stranded away from home when the expanded curfew was declared at midmorning, virtually shutting down the city.
As the gunbattle near the capital's center abated, the government eased the curfew, ending it at 5 p.m. to allow distressed residents to return home.
The pitched fighting, which left four Shiite militiamen dead, and the chaos caused by the tightened security measures plunged the capital into gloom amid stifling heat. It underscored the hurdles the Iraqi government faces in its efforts to pull back from the sectarian and insurgent violence that left dozens dead elsewhere in Iraq yesterday.
U.S. military officials said two U.S. troops were killed when their vehicle struck a roadside bomb southeast of Baghdad. The military also announced the death of three other troops in the past few days.
Meanwhile, a bomb killed worshipers at a Sunni mosque in a volatile religiously mixed agricultural region northeast of Baghdad and another killed customers standing in line for gas in the southern city of Basra.
In the northern city of Mosul, drive-by shootings have left at least 25 dead late this week.
The new Iraqi government unveiled a security plan June 14 aimed at curbing the clashes and attacks in the capital. But violence, especially in other Iraqi cities, has not abated.
Perhaps the most ominous of yesterday's many violent incidents began when about 10 vehicles carrying members of a Shiite militia, the Mahdi Army, gathered to parade through a Sunni Arab neighborhood to the Shiite Bratha mosque for noon prayer services. The mosque was the site of a suicide bombing last week that killed at least 12 people.
Neighborhood gunmen opened fire on the armed militiamen as they made their way through the streets, killing four, police said. Cars burned as the two groups exchanged fire.
Many Iraqi officials worry that such battles between young, hot-headed Shiite militiamen and Sunnis portend an all-out inter-communal civil war.
In response, Iraqi and American troops were dispatched to the scene, where the battle continued along notoriously dangerous Haifa Street, near the U.S.-controlled Green Zone. Officials said three Iraqi policemen and five Iraqi soldiers were wounded.
A Ministry of Defense official said that when the Iraqi troops arrived, they confronted 20 armed militia members brandishing AK-47s and handguns despite a June 14 weapons ban.
"The clashes lasted for two hours with the gunmen," Brig. Gen. Qassim al-Mossawi said in an interview. "During the clashes, the mosques in the neighborhoods were calling through loudspeakers for calming down and respecting the rituals of Friday prayers."
By late yesterday, the huge armed presence and extraordinary curfew had quieted the area.
The sudden midday pedestrian curfew came 10 days after enactment of the security measures that include a ban on car and truck traffic from 11 a.m. to 3 p.m. on Fridays, to prevent car bomb attacks on worshipers at city mosques.
Prime Minister Maliki has also deployed thousands of troops throughout Baghdad, snarling traffic at hundreds of checkpoints. Elsewhere in Iraq yesterday, violence continued.
A roadside bomb was detonated outside a Sunni mosque north of Baghdad as worshipers were leaving services, killing at least 10 and wounding 16.
The bomb, which police said was hidden in a plastic bag, exploded a short distance from the mosque in the village of Hibhib, where U.S. forces on June 8 killed Al-Qaida in Iraq leader Abu Musab al-Zarqawi.
"I ran out to see what's going on, and at the mosque gate there were seven or eight bodies thrown on the ground," said a 29-year-old engineer, declining to give his name, who lives near the mosque. "Those who did this did it to provoke sectarian sedition. They targeted innocent people, like the poor guards who volunteered to guard the house of God."
Later in the morning, a suicide bomber detonated his auto in a line of cars waiting to buy gasoline in the southern city of Basra, killing 11 people and wounding more than 20 others, police and witnesses said.
Authorities in the northern city of Mosul reported that 25 Iraqis, most of them Kurds, have been shot execution-style over the past two days. The corpses were found scattered in different parts of the city, a morgue official said.
J. Michael Kennedy writes for the Los Angeles Times.