A man cries in a graveyard during the funeral of Nasser Ali Afglio, a young Libyan rebel killed during battle with government troops loyal to Libyan ruler Moammar Gaddafi April 19, 2011 in Misrata, Libya. The graveyard where Nasser was buried has hundreds of simple concrete graves; many dozens are those that have been killed during the last two months of fighting in the besieged town. Thousands of civilians are trapped in Misrata as fighting continues between Libyan government forces that have surrounded the city and anti-government rebels there. (Photo by Chris Hondros/Getty Images)

The Rio Tinto river in Spain crosses an ancient mining site which makes the water turn a variety of bright colours. Copper, silver and gold are mined here, as well as iron, which turns the water red. An ochre mix is responsible for the yellow tint of the rest of the river. (Photo by Olivier Jarry-Lancombe/Solent News)

Female labourers wearing helmets take a break from laying underground electricity cables in Ahmedabad, India, March 7, 2016. (Photo by Amit Dave/Reuters)

Henry Frayne of Australia shows his ability to triple jump the lenghth of more than two Formula 1 cars during a press conference at Albert Park on February 29, 2012 in Melbourne, Australia. (Photo by Robert Prezioso/Getty Images)

Mount Sinabung is seen during an eruption from Surbakti village in Karo, North Sumatra, Indonesia, April 20, 2015. The local government is preparing the relocation of residents from three of the villages that were destroyed. (Photo by Tibta Pangin/Getty Images/Anadolu Agency)

A woman takes her souvenir picture with a white fox in front of ice sculptures illuminated by coloured lights during the opening day of the 31st Harbin International Ice and Snow Festival in the northern city of Harbin, Heilongjiang province, January 5, 2015. The annual Ice and Snow Festival, organized by China National Tourism Administration and local governments, kicked off on Monday in Harbin, one of the coldest cities in China. (Photo by Kim Kyung-Hoon/Reuters)

A Police officer checks a man wearing a carnival costume in Venice, Italy, Sunday, January 31, 2016. Carnival-goers in Venice are being asked by police to momentarily lift their masks as part of new anti-terrorism measures for the annual festivities. Police are also examining backpacks and bags and using metal-detecting wands before revelers are allowed into St. Mark's Square, the heart of the Venetian carnival. (Photo by Luigi Costantini/AP Photo)

A giant storm cloud can be seen in the sky above swimmers near Mollymook Beach, south of Sydney, March 5, 2014. (Photo by David Gray/Reuters)