Children played soccer on usually busy streets and families strolled to mosques for Friday prayers under the watchful eye of Iraqi security forces as a ban on private trucks and cars brought rare calm to the country's troubled capital.

The lull followed a night of violence during which gunmen stormed a power station and killed Shiite brick factory workers while they slept in separate attacks that killed at least 19 people in Baghdad's southeastern suburbs. The attacks raised the toll from Thursday's violence to 58.

The military also said U.S. forces detained 61 suspected insurgents in a series of raids northeast of Fallujah earlier this week.

Among those apprehended Monday were people believed to be funding and providing logistical support to suicide bombers and foreign fighters for Al Qaeda in Iraq, according to a U.S. military statement. A large amount of weapons and ammunition was also recovered and destroyed, it said.

The government imposed the 6 a.m.-4 p.m. vehicle ban Friday in a bid to avert large-scale attacks on the day Muslims congregate for the most important prayer service of the week.

Armed police and soldiers in bulletproof vests manned checkpoints as they sealed off the city of 7 million, preventing most cars and motorcycles from leaving their neighborhoods.

Militiamen loyal to radical Shiite cleric Muqtada al-Sadr also were out in force in the teeming Shiite slum known as Sadr City, helping police check cars and patrol the area.

The collaboration was likely to raise alarm among Sunni Arabs, who accuse followers of the firebrand cleric of numerous attacks against them in recent days. U.S. officials have also been pressing for the disbanding of private militias.

Shiite and Sunni leaders used their sermons to appeal for calm after the Feb. 22 bombing of a golden-domed Shiite shrine in the mostly Sunni city of Samarra unleashed a wave of reprisal attacks against Sunni mosques and other sectarian violence that killed about 500 people nationwide.

"There is no difference between Sunni and Shiite," Sheik Hadi al-Shawki told Shiite worshippers in Amarah, about 180 miles southeast of Baghdad. "We have to unite and not let the terrorists divide us."

The escalating violence has threatened to complicate the U.S. administration's goal of withdrawing more troops this year.

But the top U.S. military commander in Iraq played down suggestions the country is headed for civil war, saying the crisis appears to have passed after days of bloodshed between religious sects. But he conceded that a major new terrorist attack would threaten stability anew.

"I think it's safe to say that a major attack, particularly on a religious site, would have a significant impact on the situation here coming in the next couple of days," Gen. George Casey said in a briefing from Baghdad with reporters at the Pentagon.

In Samarra, 60 miles north of Baghdad, thousands of Sunnis gathered in the Grand Mosque, spilling out into the streets and courtyard around the devastated Askariya shrine. Cleric Ahmed Hassan al-Taha accused U.S. forces and their allies of stoking the tension between the country's majority Shiites and minority Sunnis in Iraq.

"Iraqis were living in harmony until the occupiers and those who came with them arrived in this country. They are responsible for igniting sectarianism," al-Taha said in his sermon.

Hundreds took to the streets after services in the southern Shiite stronghold of Basra and marched to the Iraqi South Oil Co., threatening to disrupt exports unless the government provides better protection and greater support to local authorities and private militias.

The capital was largely quiet Friday after overnight violence that began as a series of mortar shells slammed into the Nahrawan power station, police Lt. Bilal Ali Majed said. Half an hour later, dozens of gunmen arrived and set fire to the generating facility. Security guards returned fire, and the Iraqi police and army sent in reinforcements, he said.

At least nine people were killed and three injured in the gunbattle, police Lt. Mohammed Kheyoun said. He identified the victims as guards and technicians at the facility but did not know if any attackers were killed or wounded.

In the adjacent Maamil suburb, gunmen killed 10 Shiite southerners employed at a brick factory as they slept in their shacks, said Maj. Falah al-Mohammedawi, an Interior Ministry official. Police believed the gunmen may have been part of the same group that attacked the power station, he said.

A mortar shell slammed into a market Friday in Mahmoudiya, south of Baghdad, killing one person and wounding another, police Capt. Rasheed al-Samaraie said. Police also found two more handcuffed, blindfolded, bullet-riddled bodies in Iskandariyah, Capt. Muthana Khalid said.

An extraordinary daytime curfew and vehicle restrictions last weekend helped curb the worst of the sectarian killing, but attacks continued this week.

Prime Minister Ibrahim al-Jaafari warned preachers not to incite hatred or violence in their sermons, threatening them with "severe measures."

"Our hope is that Friday sermons be sermons of unity," al-Jaafari said in a statement late Thursday. "The street is angry and they should know how to calm the people and reassure them that the government will do all it can to pass through this period."

Downtown Baghdad was largely deserted. Most shops and gas stations were closed, though small neighborhood groceries stayed open. Dozens of young boys turned parts of Baghdad's usually busy Saadoun Street into improvised soccer fields, looking clearly unhappy when the odd car disrupted their games.

The recent surge of violence has complicated negotiations for a new, broad-based government after December parliamentary elections. U.S. officials consider an inclusive government essential if they are to start withdrawing troops before the end of the year.

Sunni Arabs walked out of the talks last week, accusing the Shiite-led government and security forces of standing by as Sunni mosques were attacked. On Thursday, the main Sunni bloc joined Kurdish and secular parties in demanding that the dominant Shiite alliance withdraw its nomination of al-Jaafari for another term as prime minister, threatening the country with new political turmoil.

Al-Jaafari won the nomination by a single vote during an election Feb. 12 among Shiite lawmakers who won seats in the Dec. 15 parliamentary election. He defeated Vice President Adil Abdul-Mahdi in large part because of al-Sadr's support.