BAGHDAD, Iraq — Four U.S. soldiers were killed and six others wounded yesterday when insurgents attacked their patrol in the northern city of Beiji. One U.S. soldier died in a suicide car bomb attack in Baghdad, officials said.

The 10 Task Force Liberty soldiers were on patrol when they came under attack late yesterday in Beiji, 155 miles north of Baghdad, a military statement said.

A suicide car bomber struck a U.S. convoy waiting at an intersection yesterday in Baghdad, killing seven people — including one American soldier — and wounding more than 90. More than a dozen others died in scattered attacks across the capital.

Also, a U.S. Marine assigned to the 2nd Marine Division was killed Monday by small-arms fire in Ramadi, 70 miles west of Baghdad, the U.S. military said.

The deaths brought the number of U.S. service members killed in Iraq this month to at least 32.

Violence raged as Iraqi political leaders showed little sign of compromise less than a week before a deadline for approving a new constitution. Faction leaders conferred for about four hours last night hoping to overcome their differences and produce a charter by Monday.

Participants said the talks focused on Kurdish demands for a federal state and although some progress was made, there was no final agreement on the issue. More talks were set for today.

The American convoy was stopped at a busy intersection when a driver detonated a vehicle packed with explosives, the U.S. Army said. Six Iraqi civilians also were killed; scores of Iraqis and two U.S. soldiers were wounded.

At least 1,836 members of the U.S. military have died since the Iraq war started in March 2003, according to an Associated Press count.

The United States hopes progress on the political front, including adoption of a democratic constitution, will help deflate the Sunni Arab-led rebellion and enable the Americans and their partners to begin withdrawing troops next year.

"It's important that they stay with their timetable" on the constitution, Defense Secretary Donald Rumsfeld said. "This will be a critical step in persuading the majority of the Iraqis that the new Iraq is worth fighting for, that they have a stake in it."

The constitution needs approval from voters in an Oct. 15 referendum. Passage would lead to elections in mid-December.