Libyan rebel fighters protect a pro-Gaddafi loyalist fighter from angry onlookers as he is brought in for medical attention to the Tripoli Central Hospital on August 25, 2011 in Tripoli, Libya. Heavy fighting continues in the Libyan capital between Gaddafi's forces and the surging rebel presence. Rebels, who have issued a $1.7m reward for Gaddafi's capture “dead or alive”, are attempting to reach Colonel Gaddafi's hometown of Sirte but have met loyalist resistance. (Photo by Daniel Berehulak/Getty Images)

A boy poses for a photo as he plays with a homemade toy gun in Qayara, south of Mosul, Iraq, Tuesday, November 22, 2016. For months, residents of the Iraqi town of Qayara have lived in the darkness from a cloud of toxic fumes released by oil fields lit by retreating Islamic State fighters. (Photo by Felipe Dana/AP Photo)

Chechen Interior Minister Ruslan Alkhanov greets participants of the military parade to mark the Victory Day in Grozny, Russia, May 9, 2015. Russia marks the 70th anniversary of the end of World War Two in Europe on Saturday with a military parade, showcasing new military hardware at a time when relations with the West have hit lows not seen since the Cold War. (Photo by Reuters/Host Photo Agency/RIA Novosti)

A dejected German Grenadier carrying a machine gun on his shoulder in front of a building on fire during the German retreat in Russia. (Photo by Keystone/Getty Images). 1944

Popular Mobilization Forces (PMF) fires towards Islamic State militants during a battle with Islamic State militants, west of Mosul, Iraq February 22, 2017. (Photo by Reuters/Stringer)

Elephants spray villagers with water in celebration of the Songkran water festival in Thailand's Ayutthaya province, north of Bangkok, April 10, 2015. The annual elephant Songkran is held to promote the tourism industry prior the Songkran Festival which is celebrated with splashing water and putting powder on each others faces as a symbolic sign of cleansing and washing away the sins from the old year. (Photo by Chaiwat Subprasom/Reuters)

Ammunition airlift into besieged Khe Sanh, Operation Pegasus, April 1968. (Photo by Larry Burrows/AP Photo)

Libyan forces allied with the U.N.-backed government fire weapons during a battle with IS fighters in Sirte, Libya, July 21, 2016. (Photo by Goran Tomasevic/Reuters)