The U.S. military used a secret aircraft painted to look like a civilian plane to carry out its first strike against an alleged drug boat in the Caribbean last September, the latest potential violation of the laws of war in the Trump administration’s wide-ranging, controversial campaign of air strikes across the region.

Axar.az informs, citing Independent, the craft involved in the attack, officials briefed on the matter told The New York Times, did not carry visible munitions under its wings and wasn’t painted with clear military markings.

Such tactics, retired Maj. Gen. Steven J. Lepper, former deputy judge advocate general for the U.S Air Force, could constitute the crime of “perfidy,” which prohibits combatants from pretending to be civilians to trick their enemies, he told the paper.