An injured fan is helped by a riot policeman during clashes between Red Star Belgrade and Partizan Belgrade fans in the stadium before the teams' Serbian Superliga soccer match in Belgrade, April 25, 2015. Serbian league leaders Partizan Belgrade held champions and bitter city foes Red Star to a 0-0 draw in a derby match marred by bad crowd trouble before kickoff on Saturday. The start was delayed for 45 minutes after home Red Star supporters pelted riot police with seats and flares, forcing officers to retreat from the north tier that houses the club's diehard fans. (Photo by Marko Djurica/Reuters)

Refugees disembark and make their way to a camp at a hotel touted as the world's most northerly ski resort in Riksgransen, Sweden, December 15, 2015. (Photo by Ints Kalnins/Reuters)

Kaylee Cantler, 15, of Waynesboro, Pa., applies blush during a natural makeup exercise at a modeling camp at the Courtyard Marriott Hotel in McLean, Va., on Monday, August 17th, 2015. (Photo by Brittany Greeson/The Washington Post)

Jessica Chastain arrives at the 72nd annual Golden Globe Awards at the Beverly Hilton Hotel on Sunday, January 11, 2015, in Beverly Hills, Calif. (Photo by Jordan Strauss/Invision/AP Photo)

Tourists pose for a selfie in Cancun, October 13, 2015. Cancun's transformation in the 1970s from a small Caribbean fishing village into a strip of nightclubs and high-rise hotels has reduced biodiversity and polluted water resources as infrastructure struggles to keep up. (Photo by Edgard Garrido/Reuters)

Xiao Jiguo, a 29-year-old actor from China's Sichuan province, reacts after shaping his eyebrows to impersonate U.S. President Barack Obama in a hotel room in the southern Chinese city of Guangzhou September 17, 2015. Xiao is taking part in the filming of a comedy film in Guangzhou, playing a low-level gangster who looks like Obama. (Photo by Bobby Yip/Reuters)