American soldiers leaping from an armoured personnel carrier during exercises in Korea, 17th March 1954. (Photo by Three Lions)

A family of refugees shelters under a truck carrying plastic lota, kettles used to perform Muslim ablutions in Muna Garage, Maiduguri, Nigeria February 16, 2017. (Photo by Paul Carsten/Reuters)

A police officer stands at a police cordon near the scene of a terror attack in London, U.K., on Sunday, June 4, 2017. A van swerved into Saturday-night crowds on London Bridge, before three men got out and went on a stabbing rampage through nearby bars. (Photo by Luke MacGregor/Bloomberg)

Medic James E. Callahan of Pittsfield, Mass., gives mouth-to-mouth resuscitation to a dying soldier in war zone D, about 50 miles northeast of Saigon, June 17, 1967. Thirty-one men of the 1st Infantry Division were reported killed in the guerrilla ambush, with more than 100 wounded. (Photo by Henri Huet/AP Photo)

Visitors look up at mock-ups of dinosaur skeletons inside the Museum of Natural History in Pyongyang on September 28, 2016. (Photo by Ed Jones/AFP Photo)

A truck driver cleans the mirror of his decorated truck in Charsadda outside Peshawar, Pakistan October 18, 2016. (Photo by Fayaz Aziz/Reuters)

The moon rises behind the skyline and financial district in Toronto, November 25, 2015. (Photo by Mark Blinch/Reuters)

Supporters of the United Democratic Party (UDP) opposition alliance presidential candidate, Adama Barrow attend a campaign rally in Buffer zone, Gambia November 29, 2016. (Photo by Thierry Gouegnon/Reuters)