The U.S. military has suffered one of its single-worst troop losses in Iraq in a roadside bomb blast near the western city of Fallujah.
In a statement Friday, the military said 10 Marines were killed and 11 wounded Thursday while they patrolled the area on foot. The device that exploded was built from several large artillery shells.
U.S. troops have been conducting anti-insurgent operations to secure the area ahead of this month's parliamentary election. Another Marine was killed in Fallujah earlier this week.
The U.S. military also reported the deaths of four American soldiers. Three were killed in a road accident near Balad today, and another died Thursday following a rocket attack in Ramadi. U.S. and Iraqi troops are conducting joint operations in Ramadi to disrupt al-Qaida-in-Iraq terrorists operating in the Euphrates River Valley.