North Korea briefly ordered its troops along the South Korean border to stand ready to fire after accusing Seoul of sending drones into its capital Pyongyang in what it called a “war provocation.”

North Korea said Sunday 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.

The powerful sister of North Korean leader Kim Jong Un has accused South Korea of deliberately avoiding responsibility for the alleged flights of South Korean drones over the North’s capital