A woman walks past a stall at a market in Banjul, Gambia December 15, 2016. (Photo by Afolabi Sotunde/Reuters)

Serbian police officers of the Special Anti-Terrorist Unit pose for a picture in their base outside Belgrade October 8, 2014. When the killing of an unarmed black teenager by a white policeman in Ferguson, Missouri, in August sparked sometimes violent protests, the response of police in camouflage gear and armoured vehicles wielding stun grenades and assault rifles seemed more like a combat operation than a public order measure. Some U.S. police departments have recently acquired U.S. military-surplus hardware from wars abroad, but there are many law enforcers around the world whose rules of engagement also allow the use of lethal force with relatively few restrictions. But for every regulation that gives police wide scope to use firearms, there is another code that sharply limits their use. In Serbia, police may use measures ranging from batons to special vehicles, water cannon and tear gas on groups of people who have gathered illegally and are behaving in a way that is violent or could cause violence, but they may use firearms only when life is endangered. (Photo by Marko Djurica/Reuters)

The sun rises over the River Brue on the Somerset Levels as temperatures in parts of the south west drop below freezing, on January, 20, 2015. (Photo by Ben Birchall/PA Wire)

An H-2A rocket carrying Japan's fourth and final quasi-zenith satellite, the Michibiki No. 4, lifts off from the Tanegashima Space Center in Kagoshima Prefecture, southwestern Japan in this photo taken by Kyodo on October 10, 2017. (Photo by Reuters/Kyodo News)

American actress Paris Jackson pulls faces at photographers during the “Melbourne Cup” race day festivities in Melbourne, Australia on November 7, 2017. (Photo by Media-Mode/Splash News and Pictures)

A Pakistani vendor prepares peanuts for sale on a roadside in Peshawar, Pakistan, 01 January 2018. After a good raining season the sales of dry fruits flourish in the country. Tourists from all over Pakistan come to Peshawar to purchase dry fruits along with other items because of price differences between different parts of the country. (Photo by Bilawal Arbab/EPA/EFE)

Performers Roni, Liv and Becky behind the scenes at Great Yarmouth Hippodrome Circus, England. (Photo by Nick Warner/The Guardian)

In this aerial photo taken on March 28, 2019 a hot air balloon flies over Putrajaya during the international hot air balloon festival in Putrajaya, Malaysia. (Photo by Mohd Rasfan/AFP Photo)