North Korean leader Kim Jong-un is said to have ordered a reorganization of some military units, including air and artillery forces.

South Korean government sources say intelligence authorities detected that reorganization efforts are underway, noting Pyongyang’s recent forward deployment of some 50 attack helicopters near the Yellow Sea border with the South.

Sources also said it is highly likely the troop reorganization was ordered by the North Korean leader since signs of movement were detected after he was seen visiting relevant military units.