Supporters of an anti-American cleric rioted in four Iraqi cities Sunday, killing eight US troops and one Salvadoran soldier in the worst unrest since the spasm of looting and arson immediately after the fall of Saddam Hussein.

The US military on Sunday reported two Marines were killed in a separate "enemy action" in Anbar Province, raising the toll of American service members killed in Iraq to at least 610.

The rioters were supporters of anti-American cleric Muqtada al-Sadr. They were angry over Saturday's arrest on murder charges of one of al-Sadr's aides, Mustafa al-Yacoubi, and the closure of a pro-al-Sadr newspaper.

Near the holy city of Najaf, a gunbattle at a Spanish garrison killed at least 22 people, including two coalition soldiers -- an American and a Salvadoran.

Fighting in the Baghdad neighborhood of Sadr City killed seven US soldiers and wounded at least 24, the US military said in a written statement.

A resident said two Humvees were seen burning in the neighborhood, and that some American soldiers had taken refuge in a building. The report could not be independently confirmed, and it was unclear whether the soldiers involved were those who died.

A column of American tanks was seen moving through the center of Baghdad Sunday evening, possibly headed toward the fighting.

The military said the fighting erupted after members of a militia loyal to radical Shiite Muslim cleric Muqtada al-Sadr took control of police stations and government buildings in the neighborhood.

Protesters clashed with Italian and British forces in other cities in a broad, violent challenge to the US-led coalition, raising questions about its ability to stabilize Iraq ahead of a scheduled June 30 handover of power to Iraqis.

With less than three months left before then, the US occupation administrator appointed an Iraqi defense minister and chief of national intelligence.

"These organizations will give Iraqis the means to defend their country against terrorists and insurgents," L. Paul Bremer said at a press conference.

About three miles outside the holy city of Najaf, supporters of al-Sadr opened fire on the Spanish garrison during a street protest that drew about 5,000 people. The protesters were angry over the arrest of the cleric's aide, said the Spanish Defense Ministry in Madrid.

The attackers opened fire at about noon, said Cmdr. Carlos Herradon, a spokesman for the Spanish headquarters in nearby Diwaniyah.

The Spanish and Salvadoran soldiers inside the garrison fired back, and assailants later regrouped in three clusters outside the base as the shooting continued for several hours.

Two soldiers -- a Salvadoran and an American -- died and nine other soldiers were wounded, the Spanish defense ministry said. No other details were available.

More than 200 people were wounded, said Falah Mohammed, director of the Najaf health department. El Salvador's defense minister said several Salvadoran soldiers were wounded.

The death toll of at least 20 included two Iraqi soldiers who were inside the Spanish base, witnesses said.

Spain has 1,300 troops stationed in Iraq, and the Central American contingent is of a similar size. The Salvadorans are under Spanish command as part of an international brigade that includes troops from Central America.

Multiple train bombings in Madrid last month that killed 191 people have been blamed on al-Qaida-linked terrorists, who said they were punishing Spain for its alliance with the United States in Iraq and Afghanistan.

Spain's new government, elected just days after the March 11 train bombings, has promised to make good on its pre-election promise to withdraw all Spanish troops from Iraq unless command for peacekeeping is turned over to the United Nations.

In El Salvador, the defense minister said the attack will not alter his country's role in reconstruction efforts.

"It reinforces even more our decision to continue helping a country that is suffering," Juan Antonio Martinez said Sunday.

The protesters were upset over the detention of al-Yacoubi, a senior aide to the 30-year-old al-Sadr, who opposes the US-led occupation of Iraq. Al-Sadr is at odds with most Shiites, who hope to gain substantial power in the new Iraqi government.

Shiites comprise about 60 percent of Iraq's 25 million people but were brutally repressed by the regime of Saddam Hussein, a Sunni Muslim.

At coalition headquarters in Baghdad, a senior official said on condition of anonymity that al-Yacoubi was detained Saturday on charges of murdering Abdel-Majid al-Khoei, a senior Shiite cleric who returned to Iraq after the US-led invasion. A total of 25 arrest warrants were issued, and 13 suspects have been arrested, the official said.

Spanish-led forces said they did not participate in the arrest.

In central Baghdad's Firdaus Square, police fired warning shots during a protest by hundreds of al-Sadr supporters against al-Yacoubi's arrest. At least two protesters were injured, witnesses said.

In Kufa, near Najaf, al-Sadr supporters took over a police station and seized guns inside. No police were in sight.

In the southern city of Nasiriyah, Italian troops traded fire with militiamen demonstrating against al-Yacoubi's detention, said Lt. Col. Pierluigi Monteduro, chief of staff of Italian troops in the region. One Italian officer was wounded in the leg.

Also in the south, British troops clashed with protesters in Amarah, according to the Ministry of Defense in London. It was unclear whether there were casualties.

Al-Sadr's office in Baghdad issued a statement later Sunday calling off street protests and saying the cleric would stage a sit-in at a mosque in Kufa, where he has delivered fiery weekly sermons for months.

Al-Sadr supporters also were angered by the March 28 closure of his weekly newspaper by US officials. The Americans alleged the newspaper was inciting violence against coalition troops.

The two US Marines, both assigned to the 1st Marine Division, were killed by an "enemy action" in Anbar Province Saturday, the military said. One died Saturday and the other Sunday, the statement said without providing details.

Anbar is an enormous stretch of land reaching to the Jordanian and Syrian borders west of Baghdad that includes Fallujah, a city where four American civilian contractors were slain Wednesday.

At a checkpoint in Samarra, about 60 miles north of Baghdad, that was manned by Iraqi Civil Defense personnel, a bomb killed three security officers and wounded another, workers at Samarra General Hospital said.

In Kirkuk, also in the north, a car bomb exploded, killing three civilians and wounding two others, police said.

Bremer on Sunday announced the appointments of Ali Allawi, the interim trade minister, as the new defense minister and Mohammed al-Shehwani, a former Iraqi air force officer who fled Iraq in 1990, as head of the Iraqi National Intelligence Service.

Late Sunday, UN envoy Lakhdar Brahimi and a team that will assist Iraqis in the political transition to an interim Iraqi government arrived in Baghdad, the United Nations said.

(China Daily April 5, 2004)