The U.S. military says coalition forces in Iraq have killed three suspected terrorists and detained 11 others during two days of clashes in central Iraq.

The military says coalition troops conducting an operation west of Tarmiyah Thursday found four people believed to be planting improvised explosive devices. It says the suspects opened fire on the troops, and the troops responded, killing three of the individuals and detaining the other one.

Separately, the military says coalition forces captured a suspected al-Qaida in Iraq member involved in weapons facilitation west of Ramadi. Coalition forces have detained nine other suspected terrorists in separate incidents since Wednesday.

The military says two civilians were killed and 25 others wounded in a mortar attack in Diyala Province Wednesday. Coalition and Iraqi security forces are investigating the incident.

On Wednesday, the U.S. State Department's chief of diplomatic security announced his resignation, one day after Secretary of State Condoleezza Rice ordered new measures to improve government oversight of private security guards in Iraq.

Richard Griffin, who served as assistant secretary of state for diplomatic security, did not mention the security firm Blackwater USA in his resignation letter.

Blackwater guards are accused of deliberately killing 17 people in Baghdad on September 16. The security firm says it responded lawfully to an attack on a U.S. diplomatic convoy.

Rice appointed a panel to examine the role of security firms in Iraq following the shooting. The new oversight measures she ordered Tuesday were recommended by the panel.

Some information for this report was provided by AFP and Reuters.