Teenagers on roller skates hold on to each other as they are pulled by a vintage car to move along a street in Havana, Cuba March 19, 2016. (Photo by Ivan Alvarado/Reuters)

A man yells for help minutes after a Serb shell hit a crowded pedestrian walkway in Sarajevo, May 1993. Radovan Karadzic, a 70-year-old former psychiatrist, still in robust health, is the most senior political figure to be convicted by the International Criminal Tribunal for the Former Yugoslavia. He was found guilty of 10 out of 11 charges. He was acquitted of a second count of genocide in Bosnian towns. (Photo by Reuters)

Tomomi Ota pushes a trolley loaded with her humanoid robot Pepper as she crosses a street in Omotesando shopping district in Tokyo, Japan, 24 March 2016. Telecommunications and mobile phone carrier SoftBank Corp. opened a robot-staffed store where 10 Pepper humanoid robots welcome customers looking to buy a mobile phone. The store will be opened until 30 March 2016. (Photo by Franck Robichon/EPA)

Young Korean women wearing hanbok (Korean traditional dress) walk inside Gyeongbok Palace on March 27, 2016 in Seoul, South Korea. There has been a trend in recent years for the young Koreans to wear the traditional Korean dress, Hanbok. Wearing the traditional dress, they will walk around downtown Seoul on weekends taking selfies, and share their memories with friends on social media, and also to promote their traditional dress to foreign visitors. (Photo by Jean Chung/Getty Images)

In this photograph taken on February 18, 2016, Pakistani children ride on swings in the predominantly Pashtun Korangi District of Karachi. In a rundown district of Karachi, Rabia balks at a neighbour's proposal to vaccinate her children, demonstrating one of the biggest hurdles to eradicating polio in Pakistan by the end of the year: confused and frightened parents. (Photo by Asif Hassan/AFP Photo)

Syrian rescue workers and residents help an injured woman following a reported air strike by government forces on the rebel-held neighbourhood of Haydariya in the northern city of Aleppo on April 10, 2016. (Photo by Thaer Mohammed/AFP Photo)

People walk during a polluted day in Shenyang, Liaoning province, March 31, 2016. (Photo by Reuters/Stringer)

A man dresses as a Minion tries to convince a tourist to have her picture taken with him, in Times Square, in New York, April 7, 2016. The assortment of costumed characters, painted naked women and ticket sellers who make the streets of New York's Times Square their office, catering to tourists, may soon be restricted after a City Council vote Thursday. (Photo by Rickey Rogers/Reuters)