North Korea has accused Seoul of a “serious provocation” following the alleged discovery of a downed South Korean drone that it claims violated North Korea’s sovereignty by scattering anti-North Korean leaflets over Pyongyang. A renewed military violation of North Korean territory would be viewed as a “declaration of war” and would lead to an “immediate retaliatory attack,” state-controlled news agency KCNA reported on Saturday citing a spokesman for the North Korean Ministry of National Defence. Last week, North Korea claimed that Seoul had sent unmanned drones carrying anti-North Korean leaf…