8-year-old Fulani boy Suleiman Yusuf drinks milk from a cow belonging to his father cattle near his family's house at Kachia Grazing Reserve, Kaduna State, Nigeria, on April 16, 2019. Kachia Grazing Reserve is an area set aside for the use of Fulani pastoralist and it is intended to be the foci of livestock development. The purpose for the grazing reserves is the settlement of nomadic pastoralists and inducement to sedentarisation through the provision of land for grazing and permanent water as way to avoid conflict. (Photo by Luis Tato/AFP Photo)

In this Monday, July 24, 2017 photo, a police officer walks in front of a mural during a protest demanding an end to the current pension fund system, in Santiago, Chile. Protesters say the government pension system robs retirees of fair pension payments, and are demanding a new social security system with higher payments. (Photo by Esteban Felix/AP Photo)

On September 1, 2004, Chechen militants stormed an elementary school in the town of Beslan in the Russian republic of North Ossetia. They took 1,100 teachers, children, and their relatives hostage, demanding the withdrawal of federal forces from Chechnya as a condition for their release. On September 3, 2004, Russian security forces stormed the building, resulting in a battle in which more than 330 hostages died, including 186 children. Here: A man assists two young hostages who managed to escape from the school building after special forces entered the school in Beslan, North Ossetia, Friday 03 September 2004. (Photo by Yuri Kochetkov/EPA)

A model presents the Flesby, a one-seater mobility concept car, during a media preview of the 45th Tokyo Motor Show in Tokyo, Japan on October 25, 2017. Japan's flagship automakers present their futuristic visions for the post-fossil fuel era at the Tokyo Motor Show that kicks off Wednesday. (Photo by Kim Kyung-Hoon/Reuters)

Comandos de Salvamento rescuers Maria Martinez (L) and Ana Chichilla attend to a wounded homeless man in San Salvador, El Salvador July 16, 2016. The man was attacked with a machete by suspected gang members. In 2015, El Salvador registered a record 103 homicides per 100,000 habitants, making it one of the most dangerous countries in the world outside a war zone. But for many young people who have few chances to distance themselves from rivalries between so-called maras in their schools and neighbourhoods, a civil-society organisation called the Comandos de Salvamento, or Rescue Corps, has been a refuge. (Photo by Jose Cabezas/Reuters)

Cloud inversion taken at Sunrise in Mam Tor, Derbyshire, UK on August 30, 2016. (Photo by David Zdanowicz/Rex Features/Shutterstock)

Kaye Don seated in the cockpit of his new racing car the “Silver Bullet” at Wolverhampton, England on February 21, 1930, in which he will attempt to beat world land speed record at Daytona. It has two 12-cylinder V shaped engines and each develops 2,000-h.p. The theoretical speed of the car is 275 m.p.h. but the designer estimated that will be able to reach 250 m.p.h. allowing for wind pressures. (Photo by AP Photo/Staff/Puttnam)

An Afghan hound arrives for the second day of the Crufts Dog Show in Birmingham, Britain March 9, 2018. The annual four-day event sees around 22,000 pedigree dogs visit the centre, before the “Best in Show” is awarded on the final day. (Photo by Darren Staples/Reuters)