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)

This handout picture taken on December 13, 2016 and released on December 14, 2016 by the Tiergarten Schoenbrunn zoo in Vienna, Austria, shows a baby sloth eating some salad as it hangs on it's mother's belly in their enclosure. The baby was born already on November 18, 2016, but according to the zoo it could be picured for the first time only now as it usually hides in it's mother's soft coat. (Photo by Daniel Zupanc/AFP Photo)

A vendor prepares paan, a betel nut-based chewable stimulant at a flower market in Kolkata, India, January 18, 2016. (Photo by Rupak De Chowdhuri/Reuters)

Muslim girls are seen after prayers, in Lagos, Nigeria, Friday, July 31, 2020. Small groups of pilgrims performed one of the final rites of the Islamic hajj on Friday as Muslims worldwide marked the start of the Eid al-Adha holiday amid a global pandemic that has impacted nearly every aspect of this year's pilgrimage and celebrations. The last days of hajj coincide with the four-day Eid al-Adha, or “Feast of Sacrifice”, in which Muslims slaughter livestock and distribute the meat to the poor. (Photo by Sunday Alamba/AP Photo)

A woman looks at an artwork during the preview of the Art Paris 2020 held at the Grand Palais in Paris, France, September 9, 2020. Originally scheduled for April, Art Paris, France's second-biggest modern and contemporary art fair, opens its door to the public from Sept. 10 to 13. (Photo by Chine Nouvelle/SIPA Press/Rex Features/Shutterstock)

A farmer harvests apples at an apple orchard on October 10, 2020 in Yiyuan County, Shandong Province of China. (Photo by Zhao Dongshan/VCG via Getty Images)

In this undated photo, the aerial view of Jingxing Bridge in autumn is shown, with trees turning red around and the West Lake going under it, in Hangzhou city, east China's Zhejiang province on November 18, 2020. (Photo by Rex Features/Shutterstock)

A parakeets lands on a woman's head at St James' Park in London, United Kingdom on February 9, 2021. London has been experiencing snow as the Storm Darcy hits the city. (Photo by Brett Cove/SOPA Images/Sipa USA)