Seoul , South Korea ( CNN ) -- North Korea apparently test-launched three short-range missiles this week , the South Korean Defense Ministry said Friday , an indication that the reclusive state 's military is operating normally after a leadership transition . `` We understand that North Korea test-fired three short-range missiles earlier this week , '' a spokesman for the Defense Ministry said Friday , speaking on condition of anonymity as is customary for South Korean military officials . He declined to comment further on the matter . North Korea often fires short-range missiles during military drills . They cause less concern in the region than longer-range missiles . The report of the test firings came nearly a month after the death of the North Korean leader Kim Jong Il , who had made the nation 's military the focal point of his 17 years in power . Pyongyang fired a short-range missile over the East Sea on December 19 , the day it announced Kim 's death to the world . The regime has since anointed Kim 's youngest son and chosen successor , Kim Jong Un , as its new `` supreme leader . '' State-run television aired video last weekend showing the younger Kim in a tank and on horseback , continuing efforts to build up his image as the rightful successor to his father . Kim Jong Un had received little attention from the North Korean state media until he emerged as the likely successor to his father in September 2010 . CNN 's Jethro Mullen contributed to this report .
Seoul says it believes North Korea fired three short-range missiles earlier this week . Short-range missile tests are common and cause less concern than longer-range ones . Comment: His youngest son and designated successor , Kim Jong Un , has become the new leader .