Somali security officers gather at the scene of a car bomb attack at the base for the African Union forces in Mogadishu, Somalia, 26 July 2016. Media reports say at least 10 people, including the security guards at the base which is located at Mogadishu's airport, have been killed after two car bombs exploded at the base. Somalia's Islamist militant group al-Shabab has claimed responsibility for the latest attack. (Photo by Said Yusuf Warsame/EPA)

Farmer Franz Schaller rides on an ox called Napoleon during a traditional ox race in the southern Bavarian village of Muensing near Lake Starnberg, Germany August 28, 2016. (Photo by Michaela Rehle/Reuters)

A resident walks on a makeshift walkway above a flooded street from the rising Rio Solimoes, one of the two main branches of the Amazon River, in Careiro da Varzea of Amazonas State, Brazil, June 30, 2015. According to the state Civil Defense, more than 460,000 people were affected by strong rains in the state. (Photo by Bruno Kelly/Reuters)

These are the dunes of the Namib Desert, taken by Korea's Kompstat-2 satellite. The blue and white area is the dried riverbed of the Tsauchab river. (Photo by The European Space Agency)

Russian pop art photographer Sergey Chilikov captures a nation liberated from the social oppression of late-era Soviet rule – at parties, in the streets, and bouncing high. His exhibition, Photoprovocations, will be at Photo London, 19-22 May. Here: Yoshkar-Ola, Matrosova Street (1995). (Photo by Sergey Chilikov)

Participants wearing masks during a hazy day at the Beijing International Marathon in front of Tiananmen Square, in Beijing, October 19, 2014. (Photo by Reuters/Stringer)

A group of youngsters dressed as ghouls and zombies for Halloween parade in downtown Lisbon, Portugal, Friday, October 31, 2014. (Photo by Francisco Seco/AP Photo)

Naked Sushi event where people eat sushi from the bodies of nearly naked models at Buddha Bar, Knightsbridge in London, United Kingdom. (Photo by Alamy Stock Photo)