A serviceman walks near an APC while a helicopter flies on the position of the Ukrainian troops in Donetsk region on August 9, 2014. Fighting with pro-Russian separatists in eastern Ukraine has left 13 troops dead in the last 24 hours, Ukraine's military said Saturday. (Photo by Anatolii Stepanov/AFP Photo)

A Santa Claus puppet holding a Christmas tree is pictured against the sun in Berlin November 23, 2014. (Photo by Hannibal Hanschke/Reuters)

French army deminers secure a helicopter in a hangar at the Gao airport, on February 9, 2013. Two Malian soldiers and four civilians have already been killed by landmines, and French troops are still fighting off what Paris called “residual jihadists” in reclaimed territory. (Photo by Pascal Guyot/AFP Photo via The Atlantic)

A Syrian refugee girl covers herself with a blanket as she stands outside tents at a makeshift settlement in Bar Elias in the Bekaa valley January 5, 2015. Lebanon enforced new immigration controls at the Syrian border on Monday in a move to gain control of the steady stream of refugees from its much larger neighbour. (Photo by Mohamed Azakir/Reuters)

In this October 15, 2014 file photo, Katsu Nakamura, sky division manager for Yamaha USA, moves the RMax unmanned helicopter into position before a demonstration of its aerial application capabilities at the University of California, Davis' Oakville Station test vineyard in Oakville, Calif. Researchers at UC Davis have been studying the effectiveness of the drone's ability for spraying pest control and nutritional materials on the test vineyard in California's Napa Valley. (Photo by Rich Pedroncelli/AP Photo)

Cast members Ryan Hansen, Kristen Bell, and Jason Dohring (L-R) pose at the premiere of “Veronica Mars” in Hollywood, California in this March 12, 2014 file photo. (Photo by Mario Anzuoni/Reuters)

A riot policeman uses a baton to hit a rioting University of Nairobi student in Kenya's capital Nairobi, in this May 20, 2014 file photo. (Photo by Noor Khamis/Reuters)

A masked reveller poses in San Marco Piazza during the Venice Carnival, January 30, 2016. (Photo by Alessandro Bianchi/Reuters)