Revellers celebrate “Ash Monday” by participating in a colourful “flour war”, a traditional festivity marking the end of the carnival season and the start of the 40-day Lent period until the Orthodox Easter, in Galaxidi, Greece February 19, 2018. (Photo by Alkis Konstantinidis/Reuters)

Israelis in costumes spray water on each other during the annual Tel Aviv Water War on Hbima Square in Tel Aviv, Israel,10 July 2015. The annual water fight is on his 11th edition. (Photo by Abir Sultan/EPA)

A hot air balloon in the likeness of Yoda from Star Wars prepares for liftoff at the 21st Philippine International Hot Air Balloon Festival at the former Clark US Air Force base in Pampanga Province, Philippines on February 9, 2017. (Photo by Xinhua News Agency/Rex Features/Shutterstock)

London Mayor Boris Johnson takes part in a tug of war with members of the armed services to launch the London Poppy Day, outside City Hall, in London, October 27, 2015. London Poppy Day is a street collection event to raise money for serving and retired members of the armed services and their families. (Photo by Stefan Wermuth/Reuters)

A soldier from the South Korean army special forces breaks stone plates with her head during a martial arts demonstration for Memorial Day at Korea War Memorial Museum in Seoul, South Korea, Monday, June 6, 2016.(Photo by Ahn Young-joon/AP Photo)

Members of the association historical recreation Frente del Nalon participate in the recreation of the battle: “The Siege of Oviedo” that took place during the Spanish Civil War, in Grullos, near Oviedo, in northern Spain, September 3, 2016. The Siege of Oviedo lasted from July 19 until October 16, 1936. The town garrison, under the command of Colonel Antonio Aranda Mata, declared for the uprising and held out until relieved by a Nationalist force. (Photo by Eloy Alonso/Reuters)

A Houthi follower with fake blood on his clothes lies on the ground to represent a victim as others perform a war dance during a ceremony marking the first anniversary of the Houthi movement's takeover of Yemen's capital Sanaa September 21, 2015. (Photo by Khaled Abdullah/Reuters)

Young Christian Lebanese women, who are members of Kataeb Phalangist party, show their skill in handling arms while they train in a village between Christian-controlled eastern port of Jounieh and the Christian village of Zahle in the west Lebanon on September 9, 1976. The Lebanese civil war erupted in April 1975. (Photo by Erich Stering/AFP Photo)