BAGHDAD, Iraq (CNN) -- At least nine U.S. soldiers were killed Monday in a pair of deadly attacks north of Baghdad, U.S. military statements released Tuesday said.

"Six Task Force Lightning soldiers died as a result of injuries sustained following an explosion near their vehicles," a statement said. The attack took place during combat operations in Salah ad Din province.

Three other soldiers were wounded and taken to military treatment facilities.

In Diyala province, three more Task Force Lightning soldiers died when a bomb exploded near them, the military said. One other soldier was wounded.

The deaths brought to 3,176 the number of U.S. troops killed in the Iraq war. Seven American civilian contractors of the military also have died in the conflict.