Blast Kills 6 as Troops Hunt Iraqi Insurgents

Rubaie said he believed that al-Qaeda in Iraq fighters remain in Himbuz and the neighboring town of Dindel.

"This is considered a main stronghold for terrorism in Diyala," he said. "The decisive battle with terrorism will be at this place."

After the combat operations, the U.S. military plans to open outposts in the province to keep a full-time security presence, as well as bring in Iraqi army and police personnel and the U.S.-funded volunteer forces to try to secure the terrain. That would be followed by humanitarian and infrastructure projects, Hertling said.

The United States has established the mainly Sunni volunteer forces in Anbar, Baghdad and elsewhere in Iraq. Coffey said commanders have already identified two tribal leaders willing to lead one of the militias in the Shirween area of northern Diyala.

U.S. officials said they would continue to pursue al-Qaeda in Iraq fighters who might still be in the area, having blended in with the local population or hidden in the lush vegetation and fields.

"We need to get after some of them palm groves," Col. Jon S. Lehr, the commander of U.S. forces in Diyala, told his battalion commanders Wednesday. "Continue to do what you're doing out there, and good hunting."

Partlow reported from Baghdad.