BAGHDAD, Iraq - U.S. forces battled insurgents loyal to Shiite cleric Muqtada al-Sadr in the Baghdad slum of Sadr City today, in clashes that killed 34 people, including one American soldier, and wounded 193, U.S. and Iraqi authorities said.

U.S. tanks moved into the neighborhood and armored personnel carriers and Bradley fighting vehicles were deployed at key intersections. Ambulances with sirens wailing rushed the wounded to hospitals as plumes of black smoke rose over the mainly Shiite neighborhood.

Warplanes flew over the sprawling neighborhood of more than 2 million, firing flares to avoid being hit by anti-aircraft missiles.

Four other soldiers were killed in separate incidents in and around Baghdad, including two members of the 13 Corps Support Command.

In the past two days, 12 Americans have been killed, bringing to 995 the number of U.S. service members who have died since the beginning of military operations in Iraq in March 2003, according to a count by The Associated Press based on Defense Department reports.

In another part of the capital, a roadside bomb targeted the Baghdad governor's convoy, killing two people but leaving him uninjured, the Interior Ministry said. Three of Gov. Ali al-Haidri's bodyguards were also hurt.

The fighting in Sadr City erupted when militants attacked U.S. forces carrying out routine patrols, killing one American, said U.S. Army Capt. Brian O'Malley.

An al-Sadr spokesman in Baghdad, Sheik Raed al-Kadhimi, blamed what he called intrusive American incursions into Sadr City and attempts to arrest the cleric's followers.

"Our fighters have no choice but to return fire and to face the U.S. forces and helicopters pounding our houses," al-Kadhimi said in a statement.

In the slum's roadways, small groups of Sadr's Mahdi militia fighters used hammers to dig up the asphalt to plant explosives. Bands of fighters in civilian clothes - mostly in their teens and early 20s - wielded rocket-propelled grenades and trotted toward the clashes, children running in their wake.

Other fighters, rifles in hand, gathered on street corners. Roads leading to the area were blocked by the militiamen using rocks and tires.

The renewed fighting came after a period of calm in the impoverished neighborhood after al-Sadr called on his followers last week to observe a cease-fire and announced he was going into politics.

But al-Sadr aides later said peace talks in Sadr City between the cleric's representatives and interim Prime Minister Ayad Allawi's government had stalled, with the government refusing militants' demands for U.S. troops to keep out of the troubled district.

Al-Sadr led a three-week uprising in the holy city of Najaf that ended 10 days ago with a peace deal that allowed his Mahdi militia fighters to walk away with their guns. The combat in Najaf left thousands dead and devastated much of the city.

Many Mahdi militiamen are believed to have returned to their stronghold in Sadr City.

Today's violence came a day after a suicide attack on a military convoy outside Fallujah killed seven U.S. Marines and three Iraqi soldiers, U.S. military officials said. It was the deadliest day for American forces in four months.

A group linked to Jordanian-born militant Abu Musab al-Zarqawi - Tawhid and Jihad - posted a statement on a Web site today claiming responsibility for the slayings.