A photo taken on August 29, 2014, shows Mount Tavurvur erupting in eastern Papua New Guinea, spewing rocks and ash into the air, forcing the evacuation of local communities and international flights to be re-routed. Mount Tavurvur, which destroyed the town of Rabaul when it erupted simultaneously with nearby Mount Vulcan in 1994, rumbled to life early in the morning on the tip of the remote island of New Britain. (Photo by Oliver Bluett/AFP Photo)

Members of the Russian Red Army Choir perform at Water Front Theatre in Beirut September 13, 2014. (Photo by Jamal Saidi/Reuters)

Horse riders perform with guns during the El-Jadida International Horse Show in El-Jadida, south of Casablanca, Morocco, October 15, 2016. (Photo by Youssef Boudlal/Reuters)

A picture shows the blood stained floor of a kindergarten following reported shelling in the rebel-held area of Harasta, on the northeastern outskirts of the capital Damascus, on November 6, 2016. At least four children were killed and 19 people injured in the government strike in Harasta, according to the Syrian Observatory for Human Rights. (Photo by Sameer Al-Doumy/AFP Photo)

A street actor dressed as a devil frightens children in downtown Prague in Prague, Czech Republic, Monday, December 5, 2016. On the eve of St. Nicholas, Czechs traditionally celebrate by dressing up as Devils, Angels and St. Nicholas, and visiting children in their homes handing out small presents, coal, potatoes or other gifts. (Photo by Petr David Josek/AP Photo)

Models wait for their turn at an audition for the upcoming Lakme Fashion Week (LFW) Summer/Resort 2017 in Mumbai, India, 14 December 2016. Around 83 national and international models participated in the audition from which five got selected. The LFW Summer/Resort 2017 is scheduled to start from 01 to 05 February 2017. (Photo by Divyakant Solanki/EPA)

Militants loyal to Yemen's exiled government ride on the back of a pick-up truck in the country's central city of Taiz August 19, 2015. Militia forces loyal to Yemen's exiled government fought their way deep into the central city of Taiz this week, local officials said, largely pushing out Houthi militiamen from the country's third largest city. (Photo by Reuters/Stringer)

A Yemeni soldier, pictured through a vehicle's windscreen, which was damaged by a bullet, gestures out of the window, in Marib, Yemen October 15, 2015. Marib is a city that is heavily armed even by the standards of Yemen, where the ready availability of weapons helped start civil war and is now preventing anyone coming out on top. Yemenis often say there are three guns for every person, a boast that has become an urgent concern in a country where the United Nations says the humanitarian situation is "critical". (Photo by Angus McDowall/Reuters)