Two cases involve a so-called general court-martial, reserved for the most serious infractions, while four involve a mid-level court called a special court-martial, according to Lt Col Robert Whetstone, a Task Force Baghdad spokesman.
Two additional cases have been completed in what is known as a summary court-martial, which hears lesser offenses, but the outcomes were not immediately available, Whetstone said on Tuesday. Four remaining cases were still under investigation, he said.
The soldiers, who were not identified, belong to the battalion's Fullerton, California-based Alpha Company. Some face charges of mistreatment of a person under their control, assault and making a false statement, while one soldier was charged with obstruction of justice, military officials have said.
The specific allegations were not disclosed, but investigators have reviewed accusations that soldiers might have used an electric stun gun to abuse handcuffed and blindfolded detainees, according to a military source who asked to remain anonymous.
"We are confident that the military justice system will address these charges fairly and appropriately, and that a just outcome will be reached,'' the National Guard said in a statement.