South Korean troops nearly shot down an American drone during a joint military exercise after a communication breakdown between the two allies' militaries, prompting a security scare near the inter-Korean border. The incident occurred as South Korean forces trained their weapons on the drone, which was launched as part of the exercise. Military units issued evacuation notices to nearby residents in the heavily fortified border region, according to media reports. The episode has underscored the need for a comprehensive review of the allies' command-and-control coordination, operational procedures, air defence capabilities and troop training, military experts said. An investigation and review are under way.