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 man lying on the ground is assisted by French policemen during clashes bewteen English and Russian supporters in the Old Port of Marseille, France, Saturday, June 12, 2016, before the UEFA EURO 2016 group B match between England and Russia. (Photo by Daniel Dal Zennaro/ANSA via AP Photo)

A fan watches the group A World Cup match between Mexico and Brazil via a live broadcast at the FIFA Fan Fest in Sao Paulo, Brazil, Tuesday, June 17, 2014. Forget the French manicure. It’s Brazil during World Cup, and women here want to flaunt their love of the national team with wacky nail designs. (Photo by Dario Lopez-Mills/AP Photo)

A US soccer fan cheers during the FIFA World Cup 2014 group A preliminary round match between Brazil and Croatia at the FIFA Fan Fest in Copacabana, Rio de Janeiro, Brazil, 12 June 2014. Brazil won 3-1. The FIFA World Cup 2014 will take place in Brazil from 12 June to 13 July 2014. (Photo by Abedin Taherkenareh/EPA)

Ghanaian fans take a selfie prior to a Group G football match between Germany and Ghana at the Castelao Stadium in Fortaleza during the 2014 FIFA World Cup on June 21, 2014. (Photo by Patrik Stollarz/AFP Photo)

A Colombian air force helicopter retrieves the bodies of victims from the wreckage of a plane that crashed into the Colombian jungle with Brazilian soccer team Chapecoense onboard near Medellin, Colombia, November 29, 2016. The chartered plane was carrying a Brazilian soccer team to the biggest match of its history when it crashed into a Colombian hillside and broke into pieces, killing 75 people and leaving six survivors, Colombian officials said Tuesday. (Photo by Jaime Saldarriaga/Reuters)

Players battle for the ball during their match at the swamp soccer China tournament in Beijing, June 26, 2014. The 32 teams from across the country participated in the soccer event to celebrate the 2014 World Cup in Brazil. (Photo by Kim Kyung-Hoon/Reuters)

Rugby Union, Hong Kong Sevens, Hong Kong Stadium on April 9, 2016: A fan wearing a mask is hugged. (Photo by Bobby Yip/Reuters)