This file photo provided on Sunday February 15, 2015 by the Syrian anti-government activist group Aleppo Media Center (AMC), which has been authenticated based on its contents and other AP reporting, shows Syrian rebels firing locally made shells against the Syrian government forces, in Aleppo, Syria. (Photo by AP Photo/Aleppo Media Center)

Commuters hang off a local passenger train in the morning in Colombo, Sri Lanka September 8, 2016. (Photo by Dinuka Liyanawatte/Reuters)

Participants dance and climb on an art installation as approximately 70,000 people from all over the world gather for the 30th annual Burning Man arts and music festival in the Black Rock Desert of Nevada, U.S. August 31, 2016. (Photo by Jim Urquhart/Reuters)

A policeman kick in the door of a residence next to the Black Panther headquarters in New Orleans as they moved in following a shootout, September 15, 1970. Other heavily armed policemen stand at ready. (Photo by Jack Thornell/AP Photo)

Australia's Jessica Lim competes in the women's nangun final during the 13th World Wushu Championship 2015 at Istora Senayan stadium in Jakarta, November 17, 2015. (Photo by Reuters/Beawiharta)

Ultra Orthodox Jews look at the body of an alleged Palestinian assailant in Jerusalem Saturday, December 26, 2015. According to a police spokeswoman, policemen approached a man who drew their suspicions just outside the Old City for following a pair of Jewish worshippers. Then he pulled out a knife and tried to stab one of them, officers opened fire and killed the assailant. (Photo by Mahmoud Illean/AP Photo)

Chingele, a herder, wears a traditional Mongol costume to greet a neighbor for the New Year. Chingele was among a group of herders who went to Beijing to protest eviction from grazing lands to make room for an army training camp. (Photo by Gilles Sabrie/The Washington Post)

People observe the landslide-affected area after the landslide at Lumle village in Kaski district July 30, 2015. Landslides triggered by torrential rain in Nepal swept through villages on Thursday, killing at least 30 people close to the nation's most popular trekking circuit, home ministry officials said. (Photo by Navesh Chitrakar/Reuters)