Fireworks illuminate the sky over downtown Seoul during the International fireworks festival 2007 at Han River on October 13, 2007 in Seoul, South Korea. The United States, Japan and South Korea have team was attending the festival. (Photo by Chung Sung-Jun/Getty Images)

South Korean girl group KARA arrive during the 21st High1 Seoul Music Awards at Olympic gymnasium on January 19, 2012 in Seoul, South Korea. (Photo by Chung Sung-Jun/Getty Images)

A South Korean diver clad in Santa Claus costume swims with sardines at The Coex Aquarium on December 8, 2012 in Seoul, South Korea. Even though the official religion of South Korea is Buddhism, about 30 percent of it is Christian and Christmas is one of the biggest holidays to be celebrated in South Korea. (Photo by Chung Sung-Jun)

Participants play with water guns during the Sinchon Water Gun Festival in Seoul, South Korea, July 9, 2016. (Photo by Kim Hong-Ji/Reuters)

Soviet Army soldiers sit on their tanks in front of the Czechoslovak Radio station building in central Prague during the first day of Soviet-led invasion to then Czechoslovakia on August 21, 1968. (Photo by Libor Hajsky/Reuters)

A man and a woman both wounded by what locals say was recent shelling by Ukrainian forces, react as they sit in an ambulance in Donetsk August 23, 2014. (Photo by Maxim Shemetov/Reuters)

A marine aims an RPG-7, a portable rocket- propelled grenade launcher, during military exercises conducted by the Russian Pacific Fleet' s naval infantry unit at the Bamburovo firing range on February 2, 2017. The drills are a part of preparations for the Suvorov Attack and Sniper Line army competitions. (Photo by Yuri Smityuk/TASS)

An Iraqi Kurdish Peshmerga takes part in a graduation ceremony at the Zakho military academy in the Iraqi Kurdish town of Zakho, some 500 kilometres north of Baghdad, on January 30, 2018. (Photo by Safin Hamed/AFP Photo)