Ri Sol-ju
North Korean leader Kim Jong Un (2nd L) and wife Ri Sol Ju (L) enjoy a joint performance given by the State Merited Chorus and the Moranbong Band celebrating the 70th founding anniversary of the Workers' Party of Korea in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on October 19, 2015. Reuters

South Korea Unification Ministry spokesman criticised North's mock military attacks on Cheong Wa Dea, the South Korean presidential residence also known as the Blue House on 12 December and termed the act "childish".

The ministry's comment comes amidst heavy criticism of the North Korea's military drill by special operations battalion (KPA Unit 525). The mock drill which included artillery shelling and infiltration into key South Korean targets was also observed by North's leader Kim Jong-un.

North Korea's national newspaper Rodong Sinmun carried images of the attack along with a lengthy report. From the leaked images, it looks like a war game designed to invade South.

North Korean media reported that Kim appreciated the drills after watching it live. "Well done, the enemy troops will have no space to hide themselves, far from taking any counteraction," he was quoted saying. In the published pictures, the Chairman of the Workers' Party of Korea was seen laughing after his military forces fired a full-scale mock-up attack of the Blue House.The report also stated that Kim has given advice on the 'guerilla warfare' invasion of the country's southern neighbour.

The South Korean officials quickly reacted to the issue with a strong condemning message."(We) view the drill from yesterday as a childish act to display that their system is undiminished, in response to our internal situation. Kim Jong Un has been continuously visiting its military units since November and it has been escalating tension. We strongly condemn it," South Korean Unification Ministry spokesman Jeong Joon-hee said.

The recent South Korean political crisis has proven to be an advantage for its neighbours. President Park Guen-hye was impeached after massive protests by citizens over corruption accusations. Last week, Defense Minister Han Min-koo, acting President Hwang Kyo-ahn also alerted that North could use the political upheaval to stir up more trouble for the Blue House and South's military forces should be well prepared for any counter attacks.

North Korea has already earned the wrath of the international community after repeated missile launches and nuclear tests, for which the UN Security Council imposed heavy sanctions. Post that, South accused its neighbours of hacking and leaking its military information.