A volcanic eruption at Mount Etna’s Vorgaine crater in Sicily, Italy on December 3, 2015. (Photo by Marco Restivo/Barcroft Media)

A man rides a horse at a playground on a hill in Kabul April 19, 2015. (Photo by Mohammad Ismail/Reuters)

A worker stack bricks on his head at a brick factory in Lalitpur January 12, 2015. (Photo by Navesh Chitrakar/Reuters)

Cats gather in front of a house damaged by shelling in the town of Dokuchayevsk, south of Donetsk, February 12, 2015. (Photo by Maxim Shemetov/Reuters)

An artist draws a tattoo on a woman's arm during a tattoo convention in Ljubljana April 18, 2015. (Photo by Srdjan Zivulovic/Reuters)

A Saudi soldier fires a mortar towards Houthi movement position, at the Saudi border with Yemen April 21, 2015. (Photo by Reuters/Stringer)

Businesswoman and vendor Sonia Maria Paypay sells clothing at a stand at the commercial zone of Gamarra in Lima, April 16, 2015. (Photo by Mariana Bazo/Reuters)

People use a board to travel on a flooded street after heavy rainfall in Baghdad, Iraq, October 31 2015. (Photo by Ahmed Saad/Reuters)