The U.N. Command (UNC) is investigating North Korea’s claim that South Korean drones flew over Pyongyang multiple times this month, after finding in the past that both Koreas violated the Korean War armistice by sending drones into each others’ airspace.

“United Nations Command is aware of the Democratic People's Republic of Korea’s claim regarding the appearance of drones over Pyongyang via open-source reporting,” the U.S.-led multinational military force said in a statement to NK News. “The command is currently investigating the matter in strict accordance with the Armistice Agreement.”