Passengers from a passing train watch as rescue workers search a train which crashed in Karachi, Pakistan, November 3, 2016. At least 17 people have been killed and dozens more injured after two trains carrying hundreds of passengers collided in Pakistan's southern port city of Karachi, officials said. (Photo by Akhtar Soomro/Reuters)

Thousands of travellers heading to their hometowns to celebrate Eid al-Fitr, the Muslim holiday to mark the end of Ramadan, wait in a traffic jam to board a ferry at the entrance to Gilimanuk port on Bali, Indonesia July 3, 2016 in this photo taken by Antara Foto. (Photo by Nyoman Budhiana/Reuters/Antara Foto)

A girl poses at an entrance of her house next to a bomb dropped by the U.S. Air Force planes during the Vietnam War, in the village of Ban Napia in Xieng Khouang province, Laos September 3, 2016. From 1964 to 1973, U.S. warplanes dropped more than 270 million cluster munitions on Laos, one-third of which did not explode, according to the Lao National Regulatory Authority. (Photo by Jorge Silva/Reuters)

A visitor looks at portraits of Mao Zedong amid his statues on display at a wholesale souvenir store in Shaoshan, Hunan Province in central China, 28 April 2016. Shaoshan is the hometown of former Communist leader Mao Zedong, popularly known as Chairman Mao. Thousands of visitors descend on this small Chinese town burrowed in the hills of Central China's Hunan province to pay homage to the “Great Helmsman” everyday. It is one of the core sites of the “Red Tourism” industry, where communist party cadres and ordinary Chinese tourists alike seek to relive the experiences and rekindle the spirit of the revolutionaries. (Photo by How Hwee Young/EPA)

In this May 14, 2016 photo, children wearing their school backpacks climb on a cliff using a bamboo ladder on their way home from school in Zhaojue county, southwest China's Sichuan province. A village in China's mountainous west where schoolchildren must climb an 800-meter (2,625-foot)-high bamboo ladder secured to a sheer cliff face may get a set of steel stairs to improve it's safety. (Photo by Chinatopix via AP Photo)

Two horses fight during a Xinhe Festival in Peixiu Village of Antai Township in Rongshui Miao Autonomous County on July 11, 2016 in Liuzhou, Guangxi Zhuang Autonomous Region of China. Xinhe Festival is one of the most popular traditional festivals in Rongshui with various entertainment activities. (Photo by VCG/VCG via Getty Images)

A monkey catches knives as it balances on a board during a daily training session at a monkey farm in Baowan village, Xinye county of China's central Henan province, February 2, 2016. Baowan village of China's central Henan province appears to be your average farming community from the surface, but at a closer look, one can hear monkey hoots from every direction. Although no official number exists, villagers say that they have been a breeding ground for both monkeys and monkey trainers for centuries. (Photo by Jason Lee/Reuters)

This picture taken on January 26, 2016 shows a monkey sitting on a bench during rehearsal at a monkey training school in a zoo in Dongying, eastern China's Shandong province. Shows featuring performing simians, popular in China and throughout Asia, are expecting a boost in the Lunar New Year of the monkey, which begins on February 8. But they are facing a growing backlash from Chinese people concerned about animal welfare. (Photo by Wang Zhao/AFP Photo)