People watch a television news screen showing a map of the epicenter of an earthquake in North Korea, at a railway station in Seoul on September 23, 2017. China's seismic service CENC on September 23 detected a zero-depth, 3.4-magnitude earthquake in North Korea, calling it a "suspected explosion". There seemed to be some initial difference of opinion, however, with Seoul's Korea Meteorological Agency (KMA) saying that it had registered a tremor of a similar size, but judged it a "natural quake". / AFP PHOTO / JUNG Yeon-Je