The Marine Corps is investigating newly surfaced photos that purport to show Marines burning the bodies of Iraqi insurgents in Fallujah in 2004.

The photos were first published Wednesday on the entertainment website TMZ.com, which says it obtained 41 photos but decided to publish only some of them because "many are just too gruesome."

An article accompanying the photos says that last week TMZ contacted the Pentagon about the photos and turned them in for their review.

A Marine spokesman confirms that the circumstances behind the photos are being investigated by the U.S. Marine Central Command. The investigation was launched in recent days after the photos obtained by TMZ were turned over to the Pentagon.

Capt. Tyler Balzer says that the investigation will "determine the veracity of the photos, what the circumstances depicted in them are, and if possible, the identities of the service members involved. " He said the results will then determine whether a broader investigation into possible wrongdoing needs to be launched.

Col. Steve Warren, who runs the Defense Press Office, says it is unclear what circumstances may have prompted the Marines to burn the remains. He said that in extremely rare cases the burning of long-dead remains may have to be done for hygienic purposes, but that it's something the investigation will have to determine.

The defiling of remains is a violation of the Uniform Code of Military Justice but the photos may also be a violation of U.S. Central Command's General Order Number One, which provides the guidelines for how American troops serving in the Middle East should conduct themselves.

Two pictures show a Marine pouring gasoline or a flammable accelerant on the remains of two males believed to be Iraqi insurgents. Additional photos show the charred remains after they had been set afire. Another picture shows a Marine posing by a human skull, presumably of someone who had been burned as well.

TMZ says that there are more than a dozen bodies shown in the pictures that they possess. Warren says the faces of the Marines have been blurred in the photos provided to the Pentagon.

In January 2012, a video surfaced of a group of Marines in Afghanistan urinating on the corpses of Taliban militants. An investigation identified the Marines and three plead guilty to charges of desecrating remains, and several others received non-judicial punishments.

At the time the Fallujah photos were purportedly taken in 2004, Fallujah had been the scene of the two bloodiest battles for U.S. military forces in Iraq. In November 2004, a force of 10,000 Marines pushed into the city in heavy street fighting, which left 100 Marines and 2,000 Iraqi insurgents dead.

Last week al Qaeda militants seized control of the city setting off a crisis for Iraq's government.