Children, some in tears, are escorted down a road in Barcelona, Spain, Thursday, August 17, 2017. Police in Barcelona say a white van has mounted a sidewalk, struck several people in the city's Las Ramblas district. (Photo by Manu Fernandez/AP Photo)

An Afghan teacher, in brown, helps school children run from the site of clashes near the Pakistan consulate in Jalalabad, capital of Nangarhar province, Afghanistan, Wednesday, January 13, 2016. Several members of the Afghan security forces were killed Wednesday after unidentified gunmen attacked the Pakistani consulate in a volatile eastern province, an official said on Wednesday. (Photo by Mohammad Anwar Danishyar/AP Photos)

Indian policemen carry the body of one of their colleagues killed in a rebel attack in the town of Dinanagar, in the northern state of Punjab, India, Monday, July 27, 2015. Indian forces fought an extended gunbattle Monday with militants who attacked a moving bus and stormed into a police station in a northern town bordering Pakistan. (Photo by Channi Anand/AP Photo)

Afghan firefighters spray water on a U.S. armoured vehicle after a suicide attack on the outskirts of Jalalabad, January 5, 2015. A suicide attacker targeted a U.S. convoy on the outskirts of Jalalabad on Monday but so far no causalities have been reported yet, provincial spokesman Ahmadzia Abdulzai said. (Photo by Reuters/Parwiz)

A victim under a blanket lays dead outside the Bataclan theater in Paris, Friday November 13, 2015. (Photo by Jerome Delay/AP Photo)

Dogs pose for a photo in the likeness of a photo time line of Face Book during the “Blocao” dog carnival parade in Rio de Janeiro, Brazil, Saturday, February 14, 2015. (Photo by Silvia Izquierdo/AP Photo)

(L-R) Maria Silva, Milena Cortes, Maria Arteaga, Jackeline Bastidas and Gissy Abello pose for a picture at the Famproa dogs shelter where they work, in Los Teques, Venezuela, August 25, 2016. Venezuelans struggling to feed their families let alone their pets are dumping animals on the streets, in parks and at makeshift homes overrun with scrawny animals amid an economic crisis. An hour from Caracas in Los Teques, hundreds of dogs bark and run around the streets scavenging for food outside a makeshift shelter. (Photo by Carlos Garcia Rawlins/Reuters)

A dog named Rama surfs a wave off Sydney's Palm Beach with its owner, Australian dog trainer and former surfing champion Chris de Aboitiz (not pictured), February 18, 2016. An Australian dog trainer and former surfing champion is using the discipline of surfing as a way of teaching owners to build healthy relationships with man's best friend. (Photo by Jason Reed/Reuters)