Japanese Ground Self-Defense Force's 1st Airborne Brigade soldiers board a CH-47 helicopter for parachute drop training during their military drill at Higashifuji training field in Susono, west of Tokyo, July 8, 2013. Japan faces increasingly serious threats to its security from an assertive China and an unpredictable North Korea, a defence ministry report said on Tuesday, as ruling politicians call for the military to beef up its ability to respond to such threats. (Photo by Issei Kato/Reuters)

Shoppers walk down stairs featuring a five-metre-high reproduction of Vincent van Gogh's signature painting “Sunflowers”, at the entrance to Ocean Terminal in Hong Kong July 15, 2013. A premium three-dimensional reproduction of works of Van Gogh, the RELIEVO collection, approved by the curators of the Van Gogh Museum in Amsterdam, is on display at a gallery inside Harbour City shopping mall attached to the terminal. (Photo by Bobby Yip/Reuters)

A driver competes in his tractor during the Tractor Pulling Euro Championships in the western German town of Fuechtorf September 9, 2012. Eighty teams from across Europe participated in the two-day competition where high-powered tractor prototypes must pull a trailer down a 100-metre (328 ft) track as far as possible. (Photo by Ina Fassbender/Reuters)

Swiss rescue workers wheel a wounded person on a stretcher after two regional trains crashed head on near Granges-Pres-Marnand near Payerne in western Switzerland July 29, 2013. The two trains collided in the Swiss canton of Vaud on Monday evening, injuring about 40 people, four seriously, Swiss news agency ATS reported. There was no immediate report of any deaths in the crash. (Photo by Denis Balibouse/Reuters)

Gers, traditional Mongolian tents, are seen on a hill in an area known as a ger district in Ulan Bator June 26, 2013. Approximately 60 percent of the population of Ulan Bator live in settlements known as ger districts and in many cases residents have limited access to basic services such as water and sanitation. According to a 2010 National Population Center census, every year between thirty and forty thousand people migrate from the countryside to the capital Ulan Bator. Ger districts in the city have been expanding rapidly in recent years. Mongolia is the world's least densely populated country, with 2.8 million people spread across an area around three times the size of France. (Photo by Carlos Barria/Reuters)

Nepal's Kumari, or living goddess, adjusts her ornament as she watches the Rato Machindranath chariot Festival in Lalitpur, Nepal, Friday, April 24, 2015. Nepal's living goddesses are young pre-pubescent girls considered by devotees to be incarnations of a Hindu goddess. Selected as toddlers, living goddesses usually keep their positions until they reach puberty. (Photo by Niranjan Shrestha/AP Photo)

Vietnamese female traffic police officers march during a rehearsal for a military parade as part of the 40th anniversary of the fall of Saigon in southern Ho Chi Minh City (formerly Saigon City), Vietnam, on April 26, 2015. Vietnam marks the 40th anniversary of the fall of Saigon on April 30, the event that ended a war that lasted over 30 years, killing up to four million Vietnamese, the Vietnamese government said, and more than 58,000 U.S troops, the U.S. Department of Defense has said. (Photo by Reuters/Kham)

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)