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)

Soldiers from 12 Mechanized Brigade perform a simulated casualty evacuation at the Ministry of Defence training area at Copehill Down on Salisbury Plain on March 9, 2012 in Wiltshire, England. The Defence Secretary Philip Hammond visited the military facility to meet soldiers from the Brigade who are shortly to deploy to Afghanistan for Operation Herrick 16, and troops from the 3rd Battalion, the Yorkshire regiment which lost five of the six men who died this week in the deadliest single attack in Afghanistan since 2001. (Photo by Matt Cardy/Getty Images)

Music student Daniele Gonzalez, (centre row, L), and Australian musician Susie Park from the Minnesota Orchestra (centre row, 2nd L), react during a rehearsal in Havana, May 15, 2015. The Minnesota Orchestra will offer two concerts in Havana and is the first major U.S. orchestra to play in Cuba since 1999. The trip cost nearly $1 million. It was underwritten by Marilyn Carlson Nelson, an heir to the Carlson hotel company fortune, and her husband Glen. The U.S. government gave special permission for a direct charter flight from Minneapolis to Havana for the event, putting 4 tons of equipment and 160 people on an Airbus 330. (Photo by Alexandre Meneghini/Reuters)

A monkey licks ice during the annual “monkey buffet” in Lopburi province, some 150 kms north of Bangkok on November 24, 2013. More than 2,000 kilos of fruits and vegetables were offered to the monkeys during the annual festival to help promote tourism in the area. (Photo by Pornchai Kittiwongsakul/AFP Photo)

Beautiful red sunset sky over Edinburgh, Scotland. Edinburgh is the capital city of Scotland and a popular tourist destination. It is also a major European financial (fund management) centre. Prominent buildings from left to right are: Edinburgh Castle, The Balmoral Hotel Clock Tower and The Scott Monument. (Photo by John Lawson/Getty Images)

A man walks on a slackline during the 7th edition of the European “Marmotte Highline Project” (MHP) festival in Lans-en-Vercors, near Grenoble, eastern France, on July 4, 2019. The event, during which the participants will be able to evolve on the various highlines located in the Regional Natural Park of Vercors, takes place until July 7, 2019. (Photo by Philippe Desmazes/AFP Photo)

Spanish MotoGP rider Joan Mir (R) of Team Suzuki Ecstar and other MotoGP racers ride mini electric motorcycles at a fan event at Twin Ring Motegi in Motegi, Japan, 17 October 2019. The event was held ahead of the MotoGP race of Japan's Motorcycling Grand Prix scheduled for 20 October 2019. (Photo by Toru Hanai/EPA/EFE)

A man stands on a mountain summit as he looks over the Inntal valley in the western Austrian village of Gnadenwald, Austria on July 18, 2017. (Photo by Dominic Ebenbichler/Reuters)