A Palestinian youth jumps with a sword as he demonstrates his ninja-style skills for the photographer in front of the ruins of buildings, that were destroyed in 2014 war, in the northern Gaza Strip January 29, 2016. The youths, who have been receiving martial arts training at local clubs in Gaza for the past two years, decided to form a team to hold regular shows in the hope that the publicity generated will eventually lead to them being invited to participate in international contests. (Photo by Mohammed Salem/Reuters)

A girl reacts as she receives polio vaccine drops during a house-to-house vaccination campaign in Yemen's capital Sanaa, November 10, 2015. (Photo by Khaled Abdullah/Reuters)

These images of young children training were taken at a gymnastics summer camp in Bozhou, Anhui province, China on July 28, 2015. Children with promise are selected to attend, and their families hope training will not only benefit their children physically but also increase ‘willpower’, according to China News Service. (Photo by ChinaFotoPress/ChinaFotoPress via Getty Images)

A Cambodian girl goes through the garbage dump looking for things to recycle in order to survive July 26, 2003 in Phnom Penh, Cambodia. Rampant corruption in this impoverished country has lead to extreme poverty with many Cambodians living below the poverty line. (Photo by Paula Bronstein/Getty Images)

A Guarani Indian woman jokes with her son in the village of Pyau at Jaragua district, in Sao Paulo April 27, 2015. The National Indian Foundation (FUNAI) has recognised 521 hectares of this area as indigenous territory, making it the smallest indigenous reserve in Brazil. Members of the Guarani community have now established a new village outside the demarcation and are being threatened with an eviction through a court order. (Photo by Nacho Doce/Reuters)

A displaced Pakistani girl collects recyclable goods from a garbage to earn living for her family in Islamabad, Pakistan, Tuesday, January 19, 2016. (Photo by B.K. Bangash/AP Photo)

A three-year-old girl smokes a cigar during the Saint Simon celebrations in San Andres Itzapa, Guatemala, on October 28, 2019. Thousands believe that the saint helps people find work, solves family problems and cures illnesses. (Photo by Orlando Estrada/AFP Photo)

Afghan children have ice cream during the Afghan New Year (Newroz) celebration in Kabul March 21, 2014. Afghanistan uses the Persian calendar which runs from the vernal equinox. The calendar takes as its start date the time when the Prophet Mohammad moved from Mecca to Medina in 621 AD. The current Persian year is 1393. (Photo by Ahmad Masood/Reuters)