A picture of an elite Marine unit posing with a flag symbol that is similar to a Nazi "SS" logo has surfaced on the Internet.

Marine Corps Scout Snipers from the 1st Reconnaissance Battalion are seen standing and kneeling with their sniper rifles in front of a blue flag with white Nazi "SS" runes. The picture was taken in 2010 in Afghanistan and the photo's description says the "SS" flag had been "adopted and used by the Marines in reference to Scout Sniper."

The Military Religious Freedom Foundation was alerted to the photo by Marines who expressed their concern, said group founder Mikey Weinstein. MRFF then distributed it to news organizations.

The Marine Corps said it became aware of the photo last November and investigated, but found it not to be racially motivated, according to a statement released by a Marine Corps spokesman, Lt. Col. Stewart Upton.

"Those involved acknowledged that the symbol could be misinterpreted and is not in keeping with our Marine Corps ethos and values," the statement said.

The unit's commander decided not to proceed with disciplinary action, it said, but all Marines in the unit were reminded that such behavior will not be tolerated and any further display could result in punishment.

"We feel these guys have no historical appreciation for what this symbol means," said a Marine official who asked not to be identified. "We think they took the symbol, thought it was cool, and didn't have an appreciation for what it meant."

In Nazi Germany, SS stood for "Schutzstaffel," the elite paramilitary force of Adolf Hitler's party.

Weinstein said the Marines who spoke out were infuriated by the photo but were worried about reprisal from their chain of command.

In a letter about the photo to the Marine Corps commandant, Gen. James Amos, Weinstein's foundation asked that "everyone associated with the matter, including anyone who condoned it, be the subject of immediate and public court-martial proceedings."

While the insignia has been unofficially used by Scout Snipers in the past, the Marine Corps said it is absolutely prohibited, the statement from Upton said.

"Certainly, the use of the "SS runes" is not acceptable and Scout Snipers have been addressed concerning this issue," the statement said. "'SS runes' are prohibited from use as a symbol or any other use."