North Korea says it has discovered the remains of a drone in Pyongyang, and that its investigation results show that it is the same type as one belonging to the South Korean military reports NHK..

The Saturday edition of North Korea's ruling Workers' Party newspaper, Rodong Sinmun, carried a statement issued by a defense ministry spokesperson.

The North has claimed that the South may have flown drones to scatter propaganda leaflets over its capital Pyongyang earlier this month.

The statement says a crashed drone was discovered on October 13, and experts determined it was the same type of reconnaissance drone displayed at a South Korean military parade held on October 1.

The document notes that the leaflet-scattering box was fixed to the underpart of the drone, indicating that it had highly likely dropped leaflets in Pyongyang.

The newspaper says the investigation will continue.

The spokesperson warned that if Pyongyang discovers and confirms a territorial violation by the South's military, it will regard it as a "declaration of war" and launch an immediate retaliatory attack.

Kim Yo Jong, the sister of North Korean leader Kim Jong Un, said in a statement on Tuesday that the country had secured "clear evidence" that South Korean forces are the "main culprit" of violating the North's sovereignty.

The South Korean military said it could not confirm if Pyongyang's claims were true.