A Kenya Wildlife Services (KWS) veterinarian and security personnel back away from a tranquilised black-Rhino calf August 30, 2017 after she appeared to prematurely overcome the sedative at the Nairobi National Park, during an identification-tagging excercise to ease quick identification of resident rhino during anti-poaching patrols. (Photo by Tony Karumba/AFP Photo)

Blankets cover the bodies of a woman (right) and a man (left background) hit by a northbound Penn Central train (background) as they waited with a crowd at Pennsylvania Railroad station in Elizabeth, N.J. on June 8, 1968 to view the southbound train carrying the body of Sen. Robert F. Kennedy to Washington. The woman was identified as Mrs. Antoinette Severini, 54, and the man, John Curia (age unavailable), both of Elizabeth. (Photo by AP Photo)

A demonstrator catches fire during clashes with riot police within a protest against Venezuelan President Nicolas Maduro, in Caracas on May 3, 2017. Venezuela's angry opposition rallied Wednesday vowing huge street protests against President Nicolas Maduro's plan to rewrite the constitution and accusing him of dodging elections to cling to power despite deadly unrest. (Photo by Ronaldo Schemidt/AFP Photo)

Children fill plastic containers with water from a well on a street, close to a neighbourhood called “The Tank” in the slum of Petare in Caracas, Venezuela, March 17, 2016. Although their nation has one of the world's biggest hydroelectric dams and vast rivers like the fabled Orinoco, Venezuelans are still suffering water and power cuts most days. The problems with stuttering services have escalated in the last few weeks: yet another headache for the OPEC nation's 30 million people already reeling from recession, the world's highest inflation rate, and scarcities of basic goods. President Nicolas Maduro blames a drought, while the opposition blames government incompetence. (Photo by Carlos Garcia Rawlins/Reuters)

People stroll alongside one of the hills of the Tio Pio park in Madrid, Monday, January 25, 2016. The park is a high viewpoint frequented mostly by locals due to its view of the Spanish capital skyline. (Photo by Francisco Seco/AP Photo)

A Hindu sadhu (holy man) smears coloured paste onto his face ahead of the forthcoming Hindu festival of “Maha Shivaratri” at the Pashupatinath temple in Kathmandu on February 11, 2018. Hindus mark the “Maha Shivratri” festival by offering special prayers and fasting, with sadhus arriving at Pashupatinath to take part in the event, which takes place on February 13. (Photo by Prakash Mathema/AFP Photo)

Deaf and hard of hearing people perform a Buddhist Guanyin Thousand Hand dance to mark Sunday's National Day for Helping the Disabled in Yunnan, Kunming province, China on May 19, 2018. (Photo by Wong Campion/Reuters)

Participants with traditional Japanese tattoos (Irezumi), related to the Yakuza, walk through the Asakusa district during the annual Sanja Matsuri festival in Tokyo on May 20, 2018. Sanja Matsuri festival is a celebration for the three founders of Sensoji Temple in the Asakusa neighbourhood with nearly two million people visiting during the three-day event. (Photo by Behrouz Mehri/AFP Photo)