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)

A man carries an injured girl after what activists said were five air strikes by forces loyal to Syria's President Bashar al-Assad in Douma, eastern al-Ghouta, near Damascus September 11, 2014. (Photo by Bassam Khabieh/Reuters)

In this photograph taken on February 15, 2021, doctor Sergen Saracoglu (L) and nurse Yilzdiz Ayten (C) from the Bahcesaray public hospital vaccination team, arrive at the village of Guneyyamac in eastern Turkey, as part of an expedition to vaccinate residents of 65 years old or above with Sinovac's CoronaVac Covid-19 vaccine. (Photo by Bulent Kilic/AFP Photo)

Belgium. Rosalie, 9, goes to school in Brussels. “At my school we have separate toilets for girls and boys on every floor. My classroom is on the 3rd floor. We have 22 toilets, which are shared between 230 pupils and 20 adults. The teachers at school let us go to the toilet whenever we need to”. (Photo by Tim Dirven/WSUP/Panos)

A child looks out from a bus window after fleeing from Ukraine to Romania, following Russia's invasion of Ukraine, at the border crossing in Siret, Romania, March 13, 2022. (Photo by Clodagh Kilcoyne/Reuters)

Belgian-British teenager Zara Rutherford closes the canopy of her Shark Ultralight airplane as she prepares to take off at the Kortrijk-Wevelgem airfield in Wevelgem, Belgium, Wednesday, August 18, 2021. A Belgian-British teenager took to the skies Wednesday in her quest to become the youngest woman to fly around the world solo. Nineteen-year-old Zara Rutherford took off from an airstrip in Wevelgem, Belgium, in an ultralight plane looking to break the record set by American aviator Shaesta Waiz, who set the world benchmark at age 30 in 2017. (Photo by Virginia Mayo/AP Photo)

Seth Moniz and Kelly Slater, of the United States, embrace after Slater won the Billabong Pro Pipeline contest just short of his 50th birthday in Haleiwa, Hawaii, US on February 5, 2022. (Photo by Brent Bielmann/World Surf League via AP Photo)

Racegoers during Ladies Day of the 2018 Cheltenham Festival in Cheltenham, England on March 14, 2018. (Photo by Graham Stone/Rex Features/Shutterstock)