Animal rights activists covered with fake blood sit on the floor during a protest against the use of animals in research to mark World Day for Animals in Laboratories in central Madrid April 24, 2014. The sign reads, “How many rabbits do your shampoo kill?”. (Photo by Andrea Comas/Reuters)

Armed Yemeni children sit in the back of a pick up truck with fighters loyal to Yemen's Saudi-backed President Abedrabbo Mansour Hadi in the Dar saad neighbourhood of the southern Yemeni city of Aden on May 10, 2015, as they continue to battle Shiite Huthi rebels. (Photo by Saleh Al-Obeidi/AFP Photo)

A handout photo made available by the World Press Photo (WPP) organization on 13 February 2017 shows a picture by Rossiya Segodnya photographer Valery Melnikov that won the Long-Term Projects – First Prize award of the 60th annual World Press Photo Contest, it was announced by the WPP Foundation in Amsterdam, The Netherlands on 13 February 2017. Caption: Civilians escape from a fire at a house destroyed by an air attack in the Luhanskaya village. (Photo by Valery Melnikov/EPA/Rossiya Segodnya/World Press Photo)

A street performer jumps in the air inside Central Park as the colors of autumn become more prevalent in New York, October 29, 2015. (Photo by Lucas Jackson/Reuters)

An Israeli woman scrambles through the mud and under barbed wire at the competition of the Legion Run in the Menara Cliffs area of Kiryat Shmona, in northern Israel, near the Lebanon border 14 October 2016. Hundreds of participants ran five kilometers cross country in steep terrain and then navigated various obstacle courses including steep inclines and mud holes. It is the first time this non-competitive but supportive sporting event is held in Israel. (Photo by Jim Hollander/EPA)

Female members of the Chinese People's Liberation Army (PLA) honour guard stand behind a string to ensure that they are in a straight line before a welcoming ceremony for Russian President Vladimir Putin outside the Great Hall of the People in Beijing, China, June 25, 2016. (Photo by Kim Kyung-Hoon/Reuters)

Students from CAS Ballet Theatre School stretch on the sidewalk Saturday, February 20, 2016, in Ann Arbor, Mich. (Photo by Junfu Han/The Ann Arbor News via AP Photo)

French firemen wearing chemical protective suits take part in a mock chemical attack exercise at the Geoffroy Guichard stadium in Saint-Etienne, France, April 4, 2016 in preparation of security measures for the UEFA 2016 European Championship. (Photo by Robert Pratta/Reuters)