Baghdad, Iraq ? An armed Shiite revolt against the American-led occupation erupted Sunday in Baghdad and in other cities across Iraq’s normally quiescent south. Nine soldiers, including eight Americans, were killed, and three dozen were wounded, U.S. officials said.

Sunday’s violence — along with the unrelated killings of two Marines in Anbar province — pushed the U.S. death toll to at least 610.

The day’s events constituted the most serious challenge yet to the U.S.-led occupation by an element of the country’s majority Shiite population, which for most of a year has observed a broad tolerance of the United States and its allies.

The fighting pitted forces led by the United States, Britain and Spain against the Mahdi Army, a militia controlled by Moqtada Sadr, a junior cleric whose following is concentrated among the urban poor.

On the decrepit eastern side of Baghdad in Sadr City, a sprawling slum named for Sadr’s father, protesters attempted to overrun police stations and other government buildings.

Militiamen fired rocket-propelled grenades and assault weapons on members of the 1st Armored Division, the U.S. military said. News photos showed militiamen and children cavorting near two Humvees in flames. Tracer fire was visible in the night sky from downtown, and residents reported loud explosions in the neighborhood after dark.

The militias were believed to have abandoned the police stations during the night, after U.S. troops cordoned off the slum, home to 2 million people. Television footage broadcast from Sadr City hospitals showed bloodied young men being wheeled into emergency rooms on gurneys and in wheelchairs. The 1st Armored Division issued a statement saying the Mahdi Army had “attempted to interfere with security in Baghdad, intimidate Iraqi citizens and place them in danger. … Coalition forces and Iraqi security forces prevented this effort and re-established security in Baghdad at the cost of seven U.S. soldiers killed and more than two dozen wounded.”

Other cities embroiled

Before the death toll from the violence in Baghdad was announced after midnight, the day’s most dramatic conflict had taken place in Kufa, near the holy city of Najaf. A lengthy firefight erupted between Salvadoran troops and a crowd of thousands of Sadr followers. The clash occurred less than a mile from the mosque where two days earlier Sadr, who has been at odds with occupation authorities for months, for the first time urged his followers to “strike” occupation forces “where you meet them.”

Demonstrators rally past a U.S. tank during an anti-American protest in Baghdad, Iraq. Demonstrations and attacks throughout southern Iraq killed at least nine soldiers Sunday, eight of whom were Americans.

Sadr issued new instructions after the firefight in Kufa, which continued for hours and eventually drew in Apache attack helicopters and U.S. warplanes. The statement advised followers to give up on demonstrations and “resort to other things.” The Arabic instruction that followed could be interpreted as “intimidate your enemies” or “terrorize your enemies.”

A Sadr spokesman said about 30 demonstrators were killed in Kufa. Survivors said the protest began as a peaceful demonstration against the arrest of a Sadr aide on Saturday on charges of conspiring in the year-old murder of a senior Shiite cleric friendly to the United States.

Military officials said one U.S. soldier and one Salvadoran soldier were killed in Kufa and that 12 coalition soldiers were wounded. Witnesses said they saw militiamen capture a Salvadoran soldier and execute him by forcing a grenade into his mouth that detonated.

Fighting also erupted in the southeastern city of Amara, where British troops said they returned fire during a protest , according to a military spokeswoman in London. News reports said one Iraqi was killed and five wounded.

In Nasariyah, 235 miles southeast of Baghdad, demonstrators took control of three bridges over the Euphrates River. The episode ended without violence after negotiations among Sadr officials, the Italian troops who control the city and the local office of the Coalition Provisional Authority, said Tobin Bradley, the CPA political adviser in the city.

Sadr officials were meeting in Basra, the country’s second-largest city, where residents said tensions were also rising.

Powerful resistance

American special operations forces join coalition soldiers as the Spanish base comes under attack outside Kufa, north of Najaf, Iraq. Gunmen opened fire on the Spanish garrison near the holy city of Najaf on Sunday during a huge demonstration by followers of an anti-American Shiite Muslim cleric.

The violence appeared to open a fresh front in resistance to the year-old occupation, during which more U.S. soldiers have been killed than in the war that overthrew the government of Saddam Hussein. Attacks on coalition forces have been focused in the so-called Sunni Triangle west and north of Baghdad, where residents with ties to the former government mounted hit-and-run attacks on U.S. patrols. Waves of terrorist bombings have targeted Westerners and Iraqis who have worked with the occupation.

Sadr loomed as an additional threat, having organized and armed a militia in the first days after the war. But except for a firefight in October in Sadr City’s central square — an encounter U.S. commanders termed an ambush — the Mahdi Army had not raised arms against coalition forces.

The posture changed over the weekend, with Sadr’s call for attacks on forces he said were trying to impose their will on Iraq.

“The Sayyid Moqtada Sadr did not call for resistance directly, but the demands of the Iraqi people are not being met,” said Abu Haider Ghalib Garawi, a Sadr official introduced as leader of the Mahdi Army. “On the contrary.

“But there’s no more patience. We can’t guarantee the behavior of the wise people and the ordinary people.”