Mexico's governmental Human Rights Commission says at least 12 and probably 15 of 22 people killed by soldiers at a rural warehouse were executed, contradicting both army and prosecutors' versions of the June 30 incident in southern Mexico.

Commission President Raul Plascencia says the scene of the killings was altered and bodies were moved to mimic a shootout — the army's initial account of how the 22 suspected gang members died.

The army's version almost immediately came under question because only one soldier was wounded. The Associated Press found evidence at the scene didn't match a shootout. A witness later told the AP that only one man died in an initial shootout and all the others were shot after surrendering.

Three soldiers face civilian murder charges and eight military discipline.