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 mother bear takes a dip in the water to cool off in the warm summer sun but refuses to leave her three youngsters behind – so they climb aboard her back. (Photo by Jon Langeland/Solent News & Photo Agency)

Actress Laetitia Casta attends the “The Meyerowitz Stories” screening during the 70th annual Cannes Film Festival at Palais des Festivals on May 21, 2017 in Cannes, France. (Photo by Stephane Mahe/Reuters)

The National Geographic Photo Ark is a travelling exhibition of photographer Joel Sartore’s quest to create a photo archive of biodiversity around the world. So far, Sartore has captured studio portraits of more than 6,000 species – a number that he hopes to double. On 1 July, the ark will open at Melbourne zoo – the first time it has been exhibited in the southern hemisphere. More than 50 portraits will be on display, including many of Australian endangered animals being protected by programs at the zoo itself. These captions have been edited from text supplied by Melbourne zoo. Here: Barking owl. (Photo by Joel Sartore/National Geographic Photo Ark/The Guardian)

People take part in a protest outside the Department for Education, London, Sunday August 16, 2020, in response to the A-level results. The British government has been urged to “get a grip” over how grades are being awarded to school students, who were unable to take exams earlier this summer because of the coronavirus pandemic. The latest confusion emerged late Saturday when England’s exam regulator launched a review on its own just-published guidance on how students can appeal grades awarded under a complicated system. (Photo by London News Pictures/The Sun)

Men walk towards law enforcement with their hands up on August 24, 2020 in Kenosha, Wisconsin. A second night of civil unrest occurred after the shooting of Jacob Blake, 29, on August 23. Blake was shot multiple times in the back by Wisconsin police officers after attempting to enter into the drivers side of a vehicle. (Photo by Brandon Bell/Getty Images)

Women walk in heavy rain as Typhoon Haishen hits Kagoshima, Kagoshima prefecture on September 6, 2020. Typhoon Haishen began to lash southern Japan on September 6, with officials warning it could bring record rainfall and winds strong enough to snap power line poles and flip cars. (Photo by Charly Triballeau/AFP Photo)

Racegoers have their temperatures checked as they make their way into the course as a pilot scheme for the return of crowds to sporting events is expected to bring in 2500 spectators during day one of the William Hill St Leger Festival at Doncaster Racecourse, England on September 9, 2020. (Photo by BackGrid/The Sun)