North Korea warns South of 'horrible disaster' if its drones found again

North Korea on Sunday warned that South Korea will face a "horrible disaster" if the latter's drones are flown again over Pyongyang.

The fresh warning, another indication of heightened tensions between the two arch-rivals, was thrown by Kim Yo-jong, the influential sister of North Korean leader Kim Jong-un, according to state-run North's Korean Central News Agency (KCNA).

Kim's remarks came just a day after North Korea floated trash-filled balloons toward South Korea, claiming Seoul had sent unmanned drones over Pyongyang three times this month.

"We have no concern about who is the main force provoking the recent drone incident and its performers," she was quoted as saying in a statement. "We will take a strong corresponding retaliatory action."

On Friday, North Korea's Foreign Ministry claimed that South Korean drones carrying leaflets were detected in the night skies over Pyongyang during the last two weeks.

It threatened to respond with force if such flights occur again.

South Korean Defense Minister Kim Yong-hyun initially rejected Pyongyang's claim but the Joint Chiefs of Staff later said it could not confirm whether North Korea's assertion was true.