North Korea said Sunday it put its front-line army units ready to launch strikes on South Korea, ramping up pressure on its rival that it said flew drones over the 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 accused South Korea of flying propaganda-filled drones over Pyongyang and threatened “retaliation,” state media reported Friday.

By Hyunsu Yim and Ju-min Park SEOUL (Reuters) -North Korea accused South Korea on Friday of sending drones to scatter a "huge number" of anti-North leaflets over its capital Pyongyang, in what it called a political and military provocation that could lead to armed conflict.