BAGHDAD, Iraq – Prime Minister al-Maliki on Tuesday ordered the lifting of joint American-Iraqi military checkpoints around the Shiite militant stronghold of Sadr City and other parts of Baghdad – another apparent move to assert his authority with the Americans and appeal to his Shiite support base.

American forces disappeared from the checkpoints within hours of the order, setting off celebrations among civilians and armed men gathered on the edge of the sprawling slum that is under the control of the Mahdi Army militia run by the radical anti-American cleric Muqtada al-Sadr.

Iraqi troops loaded coils of barbed wire and red traffic cones onto pickup trucks, while small groups of men and children danced in circles chanting slogans praising Mr. al-Sadr, who earlier Tuesday had ordered the area closed to the Iraqi government until American troops lifted what he called their “siege” of the neighborhood.

The order from Mr. al-Maliki threatened to further upset relations between America and the Iraqi government, which became strained last week after Mr. al-Maliki issued a string of bitter complaints, at one point saying he was not “America’s man in Iraq.”

The tightened security had been credited by some for producing a temporary decline in violence, possibly because they curbed the activities of Shiite death squads blamed for waves of sectarian killings of Sunnis.

But a car bomb exploded in the neighborhood on Tuesday, killing three people and wounding five, police said. On Monday, a bombing there killed at least 33 people.

Elsewhere in Baghdad, in apparently unrelated violence, a suicide car bomber struck a wedding party, killing 10 people, including four children, and wounding 12. Weddings and funerals are often public events in Iraq, making them relatively easy targets for suicide bombers hoping to spark reprisals from Sunnis and push Iraq into a full-blown civil war.

The extra checkpoints were set up last week around Sadr City as American troops searched for a missing American soldier and raided homes looking for death squad leaders in the sprawling slum that is home to an overwhelmingly Shiite population of 2.5 million people.

Other checkpoints manned by American troops were erected in the downtown Karradah neighborhood where the soldier was abducted.

Mr. al-Maliki’s statement said such measures “should not be taken except during nighttime curfew hours and emergencies.”

“Joint efforts continue to pursue terrorists and outlaws who expose the lives of citizens to killings, abductions and explosions,” said the statement, issued in Mr. al-Maliki’s name in his capacity both as prime minister and commander of Iraq’s armed forces.

In a statement addressed to local supporters on Monday, Mr. al-Sadr had warned of unspecified action if the military’s “siege” continues. He also criticized what he called the silence of politicians over actions by the American military in the district.

“If this siege continues for long, we will resort to actions which I will have no choice but to take, God willing, and when the time is right,” he said in the statement.

Mr. al-Maliki was apparently angered by a statement from Ambassador Zalmay Khalilzad that the prime minister had agreed to set a timeline for progress on reaching security and political goals – something Mr. al-Maliki denied.

American concern over the deteriorating relationship was evident when National Security Adviser Stephen Hadley showed up unannounced in Baghdad on Monday to meet with al-Maliki and his security chief, Mouwafak al-Rubaie.

American voter support for the war is at a low point as the Nov. 7 midterm elections approach, and a top aide to Mr. al-Maliki said the Iraqi leader was using the Republicans’ vulnerability on the issue to leverage concessions from the Bush administration – particularly the speedy withdrawal of American forces from Iraqi cities to American bases in the country.

Meanwhile, the American military announced the deaths of two soldiers in fighting Monday, bringing the number of troops killed in Iraq this month to 103.

October has been the fourth deadliest month for American troops since the war began in March 2003. The other highest monthly death tolls were 107 in January 2005; at least 135 in April 2004, and 137 in November 2004.

The military had no immediate comment on a CBS News report saying the top American commander in Iraq, Gen. George Casey, was expected to recommend Iraq’s ill-equipped and marginally effective security forces be increased by up to 100,000 troops. General Casey said last month that he would not rule out asking for more forces, something that could allow American troop levels to be gradually reduced.

At least three Iraqi policemen were also reported killed on Tuesday morning in Baghdad and the volatile western city of Falujah, police said.

The bodies of five unidentified people, including a woman, were found dumped early Tuesday morning in eastern Baghdad, police Maj. Mahir Hamid Mussa said. They had been tied up and blindfolded, with their bodies showing signs of torture, Mussa said.

Sheik Raed Naeem al-Juheishi, the head of a non-governmental organization dedicated to tracing the fate of victims of the former regime of Saddam Hussein, was also killed in a drive-by-shooting Monday night in Baghdad’s chaotic Dora district, Col. Mohammed Ali said.

According to an Associated Press count, October has recorded more Iraqi civilian deaths – 1,170 as of Monday – than any other month since the AP began keeping track in May 2005. The next-highest month was March 2006, when

1,038 Iraqi civilians were killed in the aftermath of the Feb. 22 bombing of an important Shiite shrine in Samarra.

Iraqi and Syrian foreign ministry officials said Syria’s foreign minister is considering a visit to Baghdad next month – the first by a top Syrian figure since Saddam Hussein’s fall in 2003

Some politicians have urged the White House to make overtures to Syria to enlist its help in solving the crisis in Iraq, where Damascus is believed to have influence with some Sunni insurgent groups.