Helicopter crash, bombing add to U.S. death toll Dawn Watson comforts her daughter, Laura, Friday, during a memorial service for Daniel Wyatt in Racine. Laura Watson had become engaged to Wyatt 12 hours before his unit was called up to go to Iraq (AP Photo/The Journal Times, Gregory Shaver). By Ashraf Khalil & Said Rifai News-Chronicle BAGHDAD, Iraq -- Two U.S. Army helicopters crashed in Baghdad on Saturday, killing two soldiers, as the military reported that four other American troops had died in car bombings elsewhere in Iraq. Insurgents also firebombed five Christian churches in the capital, causing damage but no injuries. Military officials said they were investigating what caused the helicopters to crash Saturday evening in southwest Baghdad, the capital. Two other soldiers were wounded in the crashes. The other American deaths came in two incidents in northern Iraq. A suicide car bomber struck a U.S. patrol near the town of Qaim along the Syrian border Friday, killing two soldiers, one Marine and an Iraqi translator, the U.S. military reported Saturday. Another soldier died of injuries suffered Friday in a car bombing near Mosul, about 220 miles north of the capital. Names of the deceased were withheld pending family notification. In the "Sunni Triangle" city of Fallujah, west of Baghdad, many residents fled Saturday in anticipation of a U.S. military invasion after negotiations with city leaders broke down a day earlier. U.S. forces yielded control of the rebel focal point in April, and haven't patrolled the city since. On Saturday night, American warplanes launched airstrikes against reported militant strongholds in Fallujah. Iraqi Prime Minister Ayad Allawi has issued an ultimatum to Fallujahns to turn over Jordanian militant Abu Musab Zarqawi, believed to be responsible for a series of car bombings and beheadings in Iraq. U.S. forces suspect that Zarqawi is operating openly in the city. U.S. forces and the Iraqi government are on a sustained military and political push to end parallel Sunni and Shiite-based rebellions and secure the country in advance of parliamentary elections scheduled for January. In both cases, the political approaches appear to be faltering. In Baghdad's Shiite bastion of Sadr City, militants from radical cleric Muqtada al-Sadr's Mahdi Army continued to turn over weapons as part of a peace agreement to end weeks of violent clashes in the tightly packed slum. But U.S. military officials have complained that the vast majority of suspected weaponry remains at large, and the weapons transfer, originally scheduled to end Friday, has been extended through Sunday. The series of coordinated early morning church attacks was the latest strike against the Christian minority in this predominantly Muslim country. On August, 11 people were killed when insurgents bombed five Christian churches in Baghdad and the northern city of Mosul. The bombers all struck between 4 a.m. and 5:45 a.m. In several cases, the small bomb was placed between the outer walls and main church building. The Roman Catholic church in the central Karada neighborhood sustained the heaviest damage. Windows were shattered, doors were knocked off their hinges, and a section of building wall was destroyed. Fire left scorch marks on the church walls. St. Jacobs Church in the southeast Baghdad neighborhood of Dora sustained only minimal damage. Father Saad Sirop of St. Jacobs said two altar boys who were staying overnight at the church saw a dark Opel station wagon drive up and two people plant the bomb but that they were too frightened to tell anyone. It exploded moments later, but the boys weren't hurt. Shirop called on Allawi's government to improve security for Baghdad's increasingly besieged Christian community. The wave of church bombings came as fliers were distributed in at least three neighborhoods warning of a violent insurgent campaign. The message, in the name of the Shura Council of the Iraqi Islamic Resistance, advises residents to stay in their homes and came at the beginning of the Muslim holy month of Ramadan. Father Zeya Yousef of St. George's church in Dora praised the reaction of neighborhood residents to the 4:15 a.m. blast. Muslims and Christians rushed to help extinguish the ensuing fire. "Whoever is behind this incident is trying to instigate sedition on a religious level," he said. But Yousef predicted they wouldn't succeed. The future of the fledgling peace agreement with al-Sadr, meanwhile, hinges on the extent to which U.S. and Iraqi leaders are satisfied that the Mahdi Army has disarmed. So far, the military is expressing frustration with the progress. Capt. Brian O'Malley, a spokesman for the U.S. Army's 1st Cavalry, said that the amount of weapons surrendered was just a small fraction of Sadr City's hidden arsenal. "We still haven't seen the numbers we were expecting," he said, particularly for heavy weapons such as rocket-propelled grenades, submachine guns and explosive material. "We need to have thousands and thousands of different kinds of heavy weapons," he said. "So far, we've only broken 1,000 in one category." During the first days of the transfer, which started Monday, residents mostly turned in weapons that were "unserviceable and old, basically not the type of weapons that show (the Mahdi Army) is serious about disarmament," O'Malley said. But on Friday, residents began turning in heavier, newer weapons such as mortar shells and RPGs -- occasionally by known Mahdi fighters. "We received two antiaircraft guns in perfect working order," O'Malley said. "The guys who turned it in said, `Yeah we've been shooting at your helicopters.' " The weapons transfer is being run by the Iraqi government, with U.S. troops providing security. But U.S. forces certainly will play a large role in any military push through Sadr City should the final hand-over result be deemed insufficient. Iraqi government and police officials have been meeting nightly with Sadr representatives and passing along their dissatisfaction, O'Malley said. Al-Sadr spokesman Sheik Mahmoud Sudani brushed off U.S. complaints about the hand-over, saying that they come "after five days of receiving weapons from morning to evening. Is it a pretext to launch a new attack and detain our youth after the agreement? I think they are preparing to re-attack the city." Special correspondent Raheem Salman in Baghdad contributed to this report.