BAGHDAD, Iraq (AP) – Gunmen stormed an electricity substation and slaughtered Shiite factory workers in separate attacks during a night of carnage that killed at least 19 people in Baghdad’s southeastern suburbs, police said Friday. The attacks raised the toll from Thursday’s violence to 58.

Iraqi police and soldiers took to the streets Friday in the bloodied capital to enforce a daytime ban on private vehicles in an effort to blunt a surge of sectarian violence that has pushed Iraq to the edge of civil war.

The assault 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 in pickup trucks 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 shot to death 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.

The government imposed the vehicle ban Friday in a bid to avert more attacks on the day Muslims congregate in large numbers for the most important prayer service of the week. Prime Minister Ibrahim al-Jaafari also 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.”

Security forces sealed off Baghdad, preventing most vehicles from entering or leaving the city of 7 million, said Capt. Adil Mohan of the traffic police.

Armed police and soldiers in bulletproof vests manned checkpoints across the capital, preventing most cars and motorcycles from leaving their neighborhoods.

Militiamen loyal to radical Shiite cleric Muqtada al-Sadr were also 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.

Downtown 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.

Hundreds have been killed in the violence unleashed by the Feb. 22 bombing of a revered Shiite shrine in the central city of Samarra and reprisal attacks against Sunni mosques. An extraordinary daytime curfew and vehicle restrictions last weekend helped curb the worst of the sectarian killing, but attacks continued this week.

South of Baghdad, a mortar shell slammed into a market Friday in Mahmoudiya, killing one person and injuring another, police Capt. Rasheed al-Samaraie said. And police found two more handcuffed, blindfolded, bullet-riddled bodies in Iskandariyah, said Capt. Muthana. The recent surge of violence has complicated negotiations for a new, broad-based government after December parliamentary elections, which U.S. officials consider 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.

The idea of a prime minister who owes his position to the young radical has alarmed not only Sunni Arabs and Kurds, but also several key figures in the Shiite alliance. Abdul-Mahdi was the candidate of Shiite Alliance leader Abdul-Aziz al-Hakim, who often is at odds with al-Sadr.

But the alliance does not know how to resolve the problem without risking a huge fight with al-Sadr, who is revered among impoverished Shiite militias.

Al-Jaafari adviser Haider al-Ibadi lashed out at the prime minister’s opponents Thursday, accusing them of trying to delay formation of a new government. “There are some elements who have personal differences with al-Jaafari,” al-Ibadi told The Associated Press.

“The Alliance is still sticking to its candidate.” The move against al-Jaafari also drew sharp opposition from al-Sadr.

“We will not abandon al-Jaafari,” said a close aide to the firebrand Shiite cleric. The aide spoke on condition of anonymity because of the sensitive nature of the dispute. Reda Jawad Taqi, an al-Hakim aide, said representatives of the largest parliamentary bloc would meet al-Jaafari opponents to “learn what is behind their position. We will not reject their demand (to meet). Everything is negotiable.”

The Shiites won 130 of Parliament’s 275 seats in December elections, giving them the largest bloc of lawmakers and the first chance to form a government, but not enough to govern without partners.

Also Thursday, gunmen attacked the disabled car of Iraq’s top Sunni politician, Adnan al-Dulaimi, killing one bodyguard and wounding five after al-Dulaimi sped away in another vehicle. It was not clear whether the assault was an assassination attempt, and the Sunni leader refused to blame anyone.

Soon after, other attackers shot up cars carrying security men assigned to his fellow Sunni tribesman, Defense Minister Saadoun al-Dulaimi. One bodyguard was killed and five were wounded.

Elsewhere Thursday, an explosion tore through a vegetable market in a largely Shiite Baghdad neighborhood, killing at least eight people and wounding 14. And a minibus exploded in Sadr City, killing at least five people and wounding 10. The military reported a U.S. soldier was killed during combat in insurgency-ridden Anbar province Wednesday, raising to 2,296 the number of U.S. service members who have died since the war began, according to an Associated Press count.