CNN reports in recent weeks, South Korea's defense ministry has discovered three crashed unmanned aerial vehicles (UAVs) that it believes belong to Pyongyang. Equipped with Japanese-made digital cameras, the drones captured images of important military installations and South Korea's presidential office in Seoul, according to local media reports. South Korea says the aircraft are a sign of Pyongyang's heightened surveillance that should be taken seriously, and yet officials and experts suggest the drones pose little, if any, real threat. "The small drones, presumed to have come from North Korea, don't really have great military significance," a spokesperson for South Korea's defense ministry, Kim Min-seok told reporters on Tuesday. "Even if they are to be used for future attacks,(they) can only carry 2-3 kilograms of TNT and cannot cause a huge (amount of) damage," he said.