The U.S. ambassador to Iraq pressed the country's Shiite Arab majority on Saturday to respect the rights of women and minorities as political parties worked toward a draft constitution that has stalled on issues that include the role of religion.

As debate over the constitution continued ahead of an Aug. 15 deadline to complete the new draft, U.S. tanks and helicopter gunships battled for hours in southwest Baghdad against insurgents armed with machine guns, rockets, mortars and car bombs. In western Iraq, Marines and Iraqi forces destroyed car bombs and booby-trap devices in houses and schools during a sweep through towns where attacks killed at least 22 Marines this week, the military said.

U.S. Ambassador Zalmay Khalilzad issued a statement about equal rights after a meeting with unspecified Iraqi religious leaders.

"I assured them that the United States believes strongly that the Iraqi constitution should provide equal rights before the law for all Iraqis regardless of gender, race, ethnicity, religion or sect," Khalilzad said. "There can be no compromise."

Discussion about the extent to which Iraq's constitution should follow Islamic law have fed fears by some that the Shiite-led governing coalition will impose a strict interpretation of Islam. Iraqi political leaders were scheduled to meet Sunday to seek agreement on outstanding constitutional issues, including the role of religion and the extent of federalism.

U.S. and Iraqi leaders have expressed concern that deadlines in the political process stay on track, saying that a slowdown could encourage the insurgency.

In western Iraq, U.S. Marines searched houses and caves in Haqlaniyah, Haditha and Barwana, the latest in a series of campaigns since May designed to disrupt suspected guerrilla refuges and supply lines from nearby Syria. About 200 Iraqi security force members were deployed alongside the Marines, helping to work with townspeople, said Col. Bob Chase, operations director for the 2nd Marines Division in Ramadi.

In southern Iraq, a suicide attacker blew up a car packed with explosives at a military checkpoint in the city of Hilla, killing two Iraqi policeman and three Iraqi civilians.

U.S. and Iraqi soldiers in Baghdad repelled a series of coordinated attacks on Iraqi army positions that lasted for more than two hours late Friday. Three insurgents and one Iraqi policeman were killed in the incidents, authorities said.

Special correspondent Saad Sarhan in Najaf contributed to this report.

American soldiers examine the scene of a suicide attack in Baghdad. U.S. tanks and helicopter gunships battled insurgents for hours in the capital.