In this photo taken Sunday, May 6, 2012, Denis Lutskevich, left, is detained by police during an opposition rally in Bolotnaya Square in Moscow. The former naval cadet and first-year student, 21-year-old Lutskevich was attending his first protest when he was detained, and is still in prison Monday May 6, 2013, on the first year anniversary of the protest. (Photo by Pavel Golovkin/AP Photo)

A policeman kick in the door of a residence next to the Black Panther headquarters in New Orleans as they moved in following a shootout, September 15, 1970. Other heavily armed policemen stand at ready. (Photo by Jack Thornell/AP Photo)

In this October 18, 2015 photo, contestant Carlos Angevil, Miss Gay Vargas, competes in the swimsuit category of the ninth annual Miss Gay Venezuela beauty pageant in Caracas, Venezuela. Miss Gay Venezuela requires contestants be younger than 37 and be at least 1.7 meters (5' 6" feet) tall. (Photo by Ariana Cubillos/AP Photo)

A patient buried in the hot sand looks out from under a shade that protects his face from the sun in Siwa, Egypt, August 12, 2015. In the searing heat of summer in western Egypt, at the hottest time of the day, sufferers of rheumatism, joint pain, infertility or impotence lie buried neck-deep in the sand of Siwa near Dakrour Mountain. Locals say taking a sand bath is a natural therapy with powers to cure many medical conditions. (Photo by Asmaa Waguih/Reuters)

People look at a man, who residents said was killed by al Qaeda militants, hanging on a bridge in Yemen's southeastern city of Mukalla June 17, 2015. Al Qaeda militants in Yemen killed two alleged Saudi spies, residents said, accusing them of planting tracking devices which enabled the assassination of the group's leader in a suspected U.S. drone strike. (Photo by Reuters/Stringer)

This file photo provided on Sunday February 15, 2015 by the Syrian anti-government activist group Aleppo Media Center (AMC), which has been authenticated based on its contents and other AP reporting, shows Syrian rebels firing locally made shells against the Syrian government forces, in Aleppo, Syria. (Photo by AP Photo/Aleppo Media Center)

African women in their grandmothers' clothes: Joana Choumali’s portraits show modern African women swapping jeans for kente cloth – and diving into the dazzling cultural heritage of their families. (Photo by Joana Choumali/The Guardian)

This photo taken on October 8, 2017 shows dancers posing in formation to celebrate the upcoming Party Congress, in Rongan in China' s southern Guangxi region. China will convene its 19 th Party Congress on October 18, state media said, a key meeting held every five years where President Xi Jinping is expected to receive a second term as the ruling Communist Party' s top leader. (Photo by AFP Photo/Stringer)