The U.S. military says it is investigating a video that appears to show four U.S. Marines urinating on the corpses of three Taliban fighters.

In a statement issued Wednesday, the Pentagon said it had not yet verified the “origin or authenticity” of the video, which has been posted on several websites. However, the statement condemned the video, saying the actions portrayed are not consistent with the “core values” of the U.S. military and are not indicative of the character of Marines.

In the video, four men in camouflage uniforms stand over three bloodied corpses and, at times, smile toward the camera as they appear to urinate. They laugh and make sounds of satisfaction, and one jokes, “Have a great day, buddy.”

A Muslim civil rights group in Washington also condemned the alleged desecration of corpses by U.S. Marines. The group called for “any guilty parties” to be punished to the full extent of military and U.S. law.