The number two commander of U.S. forces in Iraq says violence in the country has fallen to its lowest level since before the 2006 bombing of the Golden Mosque in Samara, which triggered reprisal sectarian killings.

Lt. General Raymond T. Odierno talks to reporters in Baghdad, 20 Sep 2007

Speaking to reporters in Baghdad Thursday, Lieutenant General Raymond Odierno said the spate of attacks in the capital has dropped about 50 percent since January, and the number of civilian casualties also has fallen.

U.S. forces began a security crackdown in Baghdad in February, and later expanded it to other provinces, targeting al-Qaida in Iraq terrorists as well as Shi'ite and Sunni Arab insurgents.

In violence Thursday, Iraqi officials say a roadside bomb blast near a police patrol in central Baghdad killed at least one person and wounded several others.

The U.S. military says coalition forces killed 10 insurgents and detained 29 suspects in operations since Wednesday. It says the raids were conducted in Baghdad and in central Iraq.

The United States and Iraq are setting up a joint commission to examine the role of private security companies operating in Iraq, following a deadly shooting incident in Baghdad involving American security contractor Blackwater USA.

U.S. and Iraqi authorities are holding separate inquiries into Sunday's incident, in which 11 Iraqi civilians were killed. Iraq has suspended Blackwater's license.

Blackwater, which provides security for U.S. government civilian employees in Iraq, says its personnel acted "lawfully and appropriately" when the convoy they were escorting came under attack.