Hundreds of Nigerians celebrate at an intersection in the flashpoint northern city of Kaduna on March 31, 2015 the victory of main opposition All Progressives Congress (APC) presidential candidate Mohammadu Buhari. (Photo by Nichole Sobecki/AFP Photo)

An exile Tibetan monk gestures as he makes a point in a dialectics debate with another monk, sitting right, at the Kirti monastery in Dharmsala, India, Monday, January 18, 2016. The debate is an essential part of their training as Buddhist monks. (Photo by Ashwini Bhatia/AP Photo)

Anti-racist Loldiers of Odin clowns speak with police as they take to the streets against anti-immigration marchers in Tampere, Finland January 23, 2016. Police prevented the groups from confronting each other. On the northern fringes of Europe, Finland has little history of welcoming large numbers of refugees, unlike neighbouring Sweden. But as with other European countries, it is now struggling with a huge increase in asylum seekers and the authorities are wary of any anti-immigrant vigilantism. (Photo by Kalle Parkkinen/Reuters/Lehtikuva)

A Thai visitor appears to be frightened by a life-size Velociraptor model also known as Raptor at the Dinosaur Planet theme park in Bangkok, Thailand, 25 March 2016. The 500 million baht (14 million US dollars or 12 million euro) theme park opening in the Thai capital aimed to attract more than 15,000 visitors a day featuring a chance to experience more than 200 dinosaurs from various species that are brought back to life. (Photo by Rungroj Yongrit/EPA)

A jockey drives a buffalo in the annual water buffalo race, part of a week-long festival in homage to the animals and in celebration of the rice harvest in Chonburi, Thailand on April 1, 2016. (Photo by Vichaya Pop/Barcroft Media)

A woman takes a picture of a Maserati's SUV model Levante during the Auto China 2016 show in Beijing, China April 25, 2016. (Photo by Kim Kyung-Hoon/Reuters)

This picture taken on September 3, 2014 shows a man taking pictures of floodwater released from the Three Gorges Dam, a gigantic hydropower project on the Yangtze river, in Yichang, central China's Hubei province, after heavy downpours in the upper reaches of the dam caused the highest flood peak of the year. Eleven people died and 27 others are missing after torrential rains battered southwest China's Chongqing, a municipality in the upper reaches of the Three Gorges Dam, causing thousands of houses to collapse, state media said. (Photo by AFP Photo/Stringer)

Two Bulgarian tourists pose in front of the Eiffel Tower in Paris on their last day in the capital on March 24, 2014. (Photo by Franck Fife/AFP Photo)