Afghan artists perform a re-enactment of the lynching of Farkhunda, a 27-year old woman, to protest against her killing in Kabul, April 27, 2015. Farkhunda, who was killed by an angry mob in front of police in the Afghan capital in March for allegedly burning a copy of Islam's holy book was wrongly accused, Afghanistan's top criminal investigator said on March 22. The killing has fuelled anger about the weak rule of law and corruption that is crippling the country's instutitions. (Photo by Omar Sobhani/Reuters)

Tong Jieping, 44-year-old mentally disabled patient, is chained by his foot inside his room, in Qunxing village of Wangjiang county, Anhui province, China, July 14, 2015. Tong was diagnosed mentally ill when he was in his 20s. His parents, both in their 70s, could not afford the medical treatments so they had to lock him up in chains to prevent him from running away, according to Tong's family. (Photo by Reuters/Stringer)

This huge male orangutan is having a right old laugh as he squints his eyes and shows his huge teeth. The orangutan, called Bimbo, was relaxing on a platform around 5m high in his enclosure when he broke out into a laugh. But his happy smile soon disappeared when another orangutan came over to see what was going on. Bimbo – the only male in the group of five apes at Leipzig Zoo, in Germany - appears to be laughing in much the same way as a human would. (Photo by Martina Radtke/Solent News)

A serene turquoise glow glimmers from underneath these powerful icebergs. Stood in the middle of Antarctica, the giant icebergs appear to be from an unearthly world. These stunning photographs were captured by American photographer Michael Leggero. “My images show pure nature, as that is how I describe Antarctica, simply pure nature”, says the 43 year old, of Carthage, New York. “It is the only place on our planet that humans have not left a presence behind”. (Photo by Michael Leggero/Hotspotmedia/Visual Press Agency)

A Uyghur boy sits atop a horse as he has his picture taken outside the Id Kah Mosque before the Eid holiday on July 28, 2014 in old Kashgar, Xinjiang Province, China. Nearly 100 people have been killed in unrest in the restive Xinjiang Province in the last week in what authorities say is terrorism but advocacy groups claim is a result of a government crackdown to silence opposition to its policies. China's Muslim Uyghur ethnic group faces cultural and religious restrictions by the Chinese government. Beijing says it is investing heavily in the Xinjiang region but Uyghurs are increasingly dissatisfied with the influx of Han Chinese and uneven economic development. (Photo by Kevin Frayer/Getty Images)

A photographer has captured these amazing rainbow-like images of stars high above the skies of Colorado. Stargazer Matt Payne, from Oregon, loves the evening skies so much, he has devoted hours to shooting the marvels of the Milky Way. The 35-year-old has to meticulously plan his work, taking into account weather, terrain, season and even the cycle of the moon to get the perfect snap. (Photo by Matt Payne/Caters News)

A person stands in front of a 25.3-meter-long giant rabbit designed by Dutch artist Florentijn Hofman at an old aircraft hangar as part of the Taoyuan Land Art Festival in Taoyuan, northern Taiwan, September 3, 2014. The rabbit is named “Moon rabbit” for the coming Mid-Autumn Festival or the Moon Festival and will be displayed from September 4 to 14 at the Taoyuan military base. (Photo by Pichi Chuang/Reuters)

A 10-year-old pet goldfish named George undergoes veterinarian Tristan Rich's scalpel to remove a life-threatening head tumor in this handout picture taken September 11, 2014 and provided to Reuters by the Lort Smith Animal Hospital in Melbourne, Australia. In a 45-minute long procedure described by Rich as “fiddly”, the fish was sedated by water laced with anaesthetic, the tumour removed and the wound sealed with tissue glue followed by antibiotics and painkillers. (Photo by Reuters/Lort Smith Animal Hospital)