In an announcement Thursday about the deaths of five troops in Anbar province, the Marines did not offer details about the incident and did not specify the troops' branch of service. It said they were "serving with the 1st Marine Expeditionary Force," the main body of Marines in Iraq.
On Friday, in its own announcement about the same incident, the Pentagon said the five were from the 1st Brigade of the Army's 1st Infantry Division and were killed when their armored personnel carrier was hit by a makeshift bomb in Habbaniyah, which is west of Fallujah. The 1st Brigade, based at Fort Riley, Kan., is operating under 1st Marine Expeditionary Force command.
The attack was typical of Iraqi insurgents. They often hide pounds of C-4, a plastic explosive, in rubble, garbage, tree trunks, guard rails and even the carcasses of dead animals, then detonate them remotely.
A Pentagon official, however, said it was unusual for Iraqis to target an M-113. The Vietnam-era personnel carrier is made by Arlington, Va.-based United Defense Industries Inc. and can carry 11 soldiers.
"I don't know of any other M-113s that have been whacked like that," he said, speaking on background. "They have been going after trucks, Humvees, and there aren't many 113s left in the infantry anymore."
The vehicle can take hits from rifles and handguns, but the M-113s in Iraq can't protect soldiers from mines or rocket-propelled grenades, United Defense Industries spokesman Doug Coffey said.
The company sells armor and mine protection kits, but the Army has not bought them, he added. The kits also can't protect M-113 crews from all types of explosive devices.
U.S. troops have developed countermeasures, such as jamming radio signals, and have set up a convoy training facility at Fort Sill, Okla., to help prepare Iraq-bound troops for the insurgency.
But the insurgents, who often are a step ahead, have two advantages in their war on troops — seemingly inexhaustible supplies of C-4 taken from old Iraqi army caches and endless miles of open roadways.