Kurdish gunmen hold their rifles in front of the burning house of a Shi'ite militiaman during clashes in Tuz Khurmato, Iraq, April 24, 2016. (Photo by Goran Tomasevic/Reuters)

Beyonce performs during the Formation World Tour at Raymond James Stadium on Friday, April 29, 2016, in Tampa, Florida. (Photo by Frank Micelotta/Invision for Parkwood Entertainment/AP Images)

Carnival revellers pose during the postponed “Rosenmontag” (Rose Monday) parade in Mainz, Germany, May 8, 2016, after the original parade in February was cancelled due to severe weather. (Photo by Ralph Orlowski/Reuters)

A man poses for a picture to show his rings of gold, silver and bronze on his fist in Zamfara, Nigeria April 21, 2016. (Photo by Afolabi Sotunde/Reuters)

Students of the General Yermolov Cadet School wait to board an airplane for a parachute jump at an airdrome in the village of Novomaryevskaya outside the southern city of Stavropol, Russia, May 13, 2016. (Photo by Eduard Korniyenko/Reuters)

The worlds largest cruise ship, the 361 metres long, Harmony of the Seas, arrives in port for her mayden voyage, in Southampton, Britain May 17, 2016. (Photo by Peter Nicholls/Reuters)

Salvadoran clown Cosquilla poses for a picture during the VIII Central America Clown Convention in San Salvador, El Salvador, May 18, 2016. (Photo by Jose Cabezas/Reuters)

A Chelsea Pensioner poses as he views displays through a floral design of Britain's Queen Elizabeth at the Chelsea Flower Show in London, Britain, May 23, 2016. (Photo by Toby Melville/Reuters)