Military helicopters fly in formation above a billboard with a picture of China's late Chairman Mao Zedong during a training session for the upcoming parade marking the 70th anniversary of the end of World War Two, on the outskirts of Beijing, July 2, 2015. Troops from Russia and Mongolia will march together with Chinese forces in a parade in Beijing in September to commemorate the end of World War Two, the government and state media said on Thursday, confirming the first two foreign participants. (Photo by Jason Lee/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)

Colombian police help carry people's household belongings across the Tachira River from Venezuela, top, to Colombia, on the border that separates San Antonio del Tachira, Venezuela from Villa del Rosario, Colombia, Tuesday, August 25, 2015, during a mass exodus of Colombians. Venezuelan President Nicolas Maduro vowed to extend a crackdown on illegal migrants from neighboring Colombia he blames for rampant crime and widespread shortages, while authorities across the border struggled to attend to droves of returning deportees. (Photo by Eliecer Mantilla/AP Photo)

Ants carry a leaf with a slogan reading “Merkel, Help!”, a reference of German Chancellor Angela Merkel, at the zoo in Cologne, Germany August 18, 2015. Some of the zoo's 500,000 leaf-cutting ants carry laser-cut leaves with slogans during a campaign to protect the Amazon rain forest, organised by the German branch of World Wild Fund for Nature (WWF) and Cologne Zoo. Picture taken through the glass of the display case. (Photo by Ina Fassbender/Reuters)

A municipal police officer throws a stone back at protesting residents of Kampung Pulo after clashes erupted during an eviction in Jakarta, Indonesia, August 20, 2015 in this photo taken by Antara Foto. Residents facing eviction from a flood-prone part of Indonesia's capital of Jakarta clashed with police on Thursday, prompting security forces to fire tear gas and water cannon. (Photo by Muhammad Adimaja/Reuters/Antara Foto)

In this handout image provided by Taronga Zoo, an unnamed baby Goodfellows Tree Kangaroo joey is seen in it's mothers pouch on March 10, 2014 in Sydney, Australia. Taronga Zoo is celebrating the successful birth of its first Goodfellows Tree Kangaroo joey in more than 20 years. Zookeepers have only just begun seeing her peeking out from first-time mother, Qwikilas, pouch after she was born in September last year. (Photo by Taronga Zoo via Getty Images)

With a presence in nearly every city and town across Iran, the paramilitary Basij volunteer corps has an ever-increasing influence on life in the Islamic Republic. Authorities created the Basij, which means mobilization in Persian, just after the country's 1979 Islamic Republic. It is part of Iran's powerful Revolutionary Guard. Photo: In this Thursday, August 22, 2013 photo, a female member of the Basij paramilitary militia aims a rifle as a trainer looks over her shoulder in Tehran, Iran. (Photo by Ebrahim Noroozi/AP Photo)