The U.S. military has carried out air strikes in western Iraq, which it says killed a known terrorist, and several other suspected terrorists.
Early Tuesday, American warplanes bombed what the military says were three terrorist safe houses in two towns in Husaybah and Karabilah near the Syrian border.
The military said several militants were killed, but exact numbers were not known. Arabic television channel al-Jazeera reported at least 40 dead.
In other developments, the U.S. ambassador to Iraq suggested there could still be changes to the draft constitution presented Sunday to parliament.
Standing beside a prominent Sunni Arab political leader, Adnan al-Dulaimi, Ambassador Zalmay Khalilzad told reporters on Tuesday that a "final, final draft" has not been presented yet. His statement suggested the United States has not given up hope of winning the endorsement of Sunni Arab leaders for the constitution.