Libyan forces allied with the U.N.-backed government fire a shell at Islamic State fighters' positions in Sirte, Libya August 15, 2016. (Photo by Ismail Zitouny/Reuters)

Valentin Arias Delgado and Diana Franco Durango, from Colombia, perform their routine at the Stage style Tango World Championship, in Buenos Aires, Argentina, August 31, 2016. (Photo by Enrique Marcarian/Reuters)

African migrants stranded in Costa Rica walk near garbage on the Inter-American highway at the border between Costa Rica and Nicaragua, in Penas Blancas, Costa Rica, September 8, 2016. (Photo by Juan Carlos Ulate/Reuters)

A woman carrying an inflatable doll crosses Withy Grove in Manchester, UK on September 11, 2016. Revellers out in Manchester City Centre. (Photo by Joel Goodman/London News Pictures)

Shaolin monks of the Dengfeng Zhongyue Shaolin Boxing Culture Troupe from Henan Province in China perform in Valletta, Malta, September 17, 2016. (Photo by Darrin Zammit Lupi/Reuters)

A model is groomed backstage of the Fashion East catwalk show during London Fashion Week Spring/Summer 2017 in London, Britain September 17, 2016. (Photo by Neil Hall/Reuters)

Lightning strikes during a storm over the Ionian Sea in Calabria, Italy on June 27, 2016. (Photo by Alfonso Di Vincenzo/Pacific Press/Rex Features)

Fashion fans pose outside the main catwalk venue during London Fashion Week Spring/Summer 2017 in London, Britain September 20, 2016. (Photo by Neil Hall/Reuters)