A woman performs during a march to commemorate International Day for the Elimination of Violence Against Women, in Bogota, November 25, 2015. (Photo by John Vizcaino/Reuters)

A pig's head is seen in a basin after it was slaughtered it in the village of Azerany, Belarus, December 12, 2015. (Photo by Vasily Fedosenko/Reuters)

Damaged buildings are pictured at night in Aleppo, Syria December 11, 2015. (Photo by Ammar Abdullah/Reuters)

Passengers travel on the London train and underground system during the Christmas party season, December 18, 2015. (Photo by Paul Hackett/Reuters)

Hao Han (8), Shaolin kung fu student and child actor. Shaolin Monastery, Henan. (Photo by Mathias Braschler and Monika Fischer)

Synalpheus iocasta; Singapore Marine. (Photo by Arthur Anker)

The 33-year-old Norwegian rightwing extremist Anders Behring Breivik, who killed 77 people in twin attacks in Norway last year, arrives at a courtroom. (Photo by Heiko Junge/AP File Photo)

These photos and video were taken in the Russian city of Astrakhan on the evening of June 7th, 2012. (Photo by Maxim Korotshenko)