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)

A person dressed like a zombie walks during the 2015 Comic-Con International Convention in San Diego, California July 9, 2015. The pop-culture held at the San Diego Convention Center event runs July 9-12. (Photo by Mario Anzuoni/Reuters)

A model walks the runway at the Jacob Birge Vision show during London Fashion Week Fall/Winter 2015/16 at Fashion Scout Venue on February 23, 2015 in London, England. (Photo by Ben A. Pruchnie/Getty Images)

Women in costumes walk as they participate in Halloween celebrations in the downtown of Seoul, South Korea, October 31, 2015. (Photo by Kim Hong-Ji/Reuters)

Attendees at Wizard World Comic Con walk through hallways in Chicago, Illinois, United States, August 22, 2015. (Photo by Jim Young/Reuters)

People walk along a street with long-tailed macaques in Lopburi, north of Bangkok November 29, 2015. (Photo by Jorge Silva/Reuters)