North Korea's artillery units near the border with South Korea have been ordered to be ready to fire amid frictions over drones that Pyongyang says are being flown over the frontier, state media cited the government as saying on Sunday.

North Korea says its front-line army units are ready to launch strikes on South Korea after accusing its rival of flying drones over the capital Pyongyang.

North Korea says South Korea flew propaganda-dropping drones over its capital city, warning the "safety lock on our trigger has now been released" in response.