Women take part in a march in Santiago on October 19, 2016, to protest against violence against women and in solidarity for the brutal killing of a 16- year- old girl in Mar del Plata, Argentina last week The killing, in which the high school student was allegedly raped and impaled on a spike by drug dealers, is just the latest incident of horrific gender violence in Argentina, which has seen more than a year of mass marches to protest brutality against women. (Photo by Claudio Reyes/AFP Photo)

A Shiite fighter from the Hashed al-Shaabi (Popular Mobilisation) patrols in the village of Ayn Nasir, south of Mosul, on October 29, 2016, after recapturing it from Islamic State group jihadists in an ongoing operation to retake the city of Mosul. Iraqi paramilitary forces launched an operation to cut the Islamic State group's supply lines between its Mosul bastion and neighbouring Syria, opening a new front in the nearly two-week-old offensive. (Photo by Ahmad Al-Rubaye/AFP Photo)

Skeletons are arranged in a bar scene as part of a competition to create Day of the Dead altars on pedestrian Regina Street in central Mexico City, Tuesday, November 1, 2016. The holiday honors the dead as friends and families gather in cemeteries to decorate their loved ones' graves and hold vigil through the night on Nov. 1 and 2. (Photo by Rebecca Blackwell/AP Photo)

An American flag is visible in the windows of the cupola aboard the International Space Station. Thanks to a bill passed by Texas legislators in 1997 that put in place technical voting procedure for astronauts – nearly all of whom live in Texas – they have the ability to vote from space through specially designed absentee ballots. To preserve the integrity of the secret vote, the ballot is encrypted and only accessible by the astronaut and the county clerk responsible for casting the ballot. (Photo by NASA)

Baker Magadma, a member of Palestinian sports group Bar Palestine, performs on the street in Gaza City, on June 3, 2016. Street workout, which is still new in Gaza, is a growing sport across the world with annual competitions and events. (Photo by Mohammed Abed/AFP Photo)

Beneath the Swedish capital lies an intricate web of underground train lines. More than 90 of the 100 stations in the 110km tunnel system, sometimes referred to as “the world’s longest art gallery”, have been decorated with paintings, installations, mosaics and sculptures by 150 artists since the 1950s. After spending a couple of weeks exploring arctic Norway and Sweden, London-based travel photographer Conor MacNeill headed underground to capture images of the metro stations. Here: A rainbow arcs over a girl on the platform of Stadion station. (Photo by Conor MacNeill/The Observer)

A Hindu devotee performs a stunt with fire during a rehearsal for the annual Rath Yatra, or chariot procession, which commemorates a journey by Hindu god Jagannath, his brother Balabhadra and sister Subhadra, in specially made chariots, in Ahmedabad, India, June 26, 2016. (Photo by Amit Dave/Reuters)

A man lays in front of a tank in the entrance to Istanbul's Ataturk airport, early Saturday, July 16, 2016. Members of Turkey's armed forces said they had taken control of the country, but Turkish officials said the coup attempt had been repelled early Saturday morning in a night of violence, according to state-run media. (Photo by Ismail Coskun/IHA via AP Photo)