Civilians are led by members of pro-Russian self-defence units as they run outside a military base during an assault in the Crimean town of Belbek near Sevastopol March 22, 2014. Russian troops forced their way into a Ukrainian airbase in Crimea with armored vehicles, automatic fire and stun grenades on Saturday, injuring a Ukrainian serviceman and detaining the base's commander for talks. (Photo by Vasily Fedosenko/Reuters)

A baby giant panda plays at Chengdu Research Base of Giant Panda Breeding in Chengdu, Sichuan province, China, January 22, 2017. (Photo by Jason Lee/Reuters)

Civil security aircrafts parade during the inauguration of the Nimes-Garons civil security air force base on March 10, 2017 in Nimes, southern France. (Photo by Pascal Guyot/AFP Photo)

Ecuadorean spontaneous bullfighters participate in a popular bull festival called Las Canteras del Antisana at Pinantura village on the base of the Antisana volcano in Quito, November 28, 2015. (Photo by Guillermo Granja/Reuters)

Indian Air Force personnel parade during the 85th Air Force Day celebrations at Hindon Air Force base in Ghaziabad on October 8, 2017. (Photo by AFP Photo/Stringer)

Iraqi security forces ride in vehicles travelling to Mosul to fight against militants of Islamic State at an Iraqi army base in Camp Taji in Baghdad, February 21, 2016. (Photo by Ahmed Saad/Reuters)

Chinese special policemen rank in a line of battle during an anti-terror drill at a training base of Chengdu Armed Police Headquarters on September 28, 2005 in Chengdu of Sichuan Province, China. (Photo by China Photos/Getty Images)

Members of the Kaisokah Moko Jumbies perform with fire on the waterfront near their San Fernando, Trinidad base February 10, 2015. (Photo by Andrea De Silva/Reuters)