North Korea has said its front-line army units are ready to launch strikes on South Korea, ramping up pressure on its rival that it said flew drones and dropped leaflets over its capital Pyongyang. South Korea has refused to confirm whether it sent drones but warned it would sternly punish North Korea if the safety of its citizens is threatened.

North Korea had, on Friday, accused South Korea of launching drones to drop propaganda leaflets over Pyongyang three times this month and threatened to respond with force if it happened again.