An Indian Sikh devotee takes a dip in the holy sarover (water tank) at the Golden Temple on the eve of “Ghallughara Diwas”, the 29th Anniversary of Operation Bluestar, in Amritsar on June 5, 2013. The 1984 assault on the Golden Temple complex by the Indian army was conducted in an attempt to arrest separatists Sikh leader Sant Jarnail Singh Bhindranwale and his militant followers who had initiated a movement for a separate Sikh state. (Photo by Narinder Nanu/AFP Photo)

Caroline Wozniacki of Denmark serves in her match against Kaia Kanepi of Estonia during day four of the Toray Pan Pacific Open at Ariake Colosseum on September 28, 2011 in Tokyo, Japan. (Photo by Koji Watanabe/Getty Images)

Chinese butchers catch a pig to slaughter on January 31, 2005 in Jinzhai County, Anhui Province, China. (Photo by Cancan Chu/GettyImages)

Victor Peralta from Uruguay gestures during the fourth International Tattoo Convention in Quito, September 25, 2016. (Photo by Kevin Granja/Reuters)

The ruins of a castle stand above the town of Rocca Calascio, close to Santo Stefano di Sessanio in the province of L'Aquila in Abruzzo, inside the national park of the Gran Sasso e Monti della Laga, Italy, September 7, 2016. (Photo by Siegfried Modola/Reuters)

A member of Sakura circus team performs during the second day of a one week show in Padukka, near Colombo, Sri Lanka November 28, 2016. (Photo by Dinuka Liyanawatte/Reuters)

This picture taken on October 20, 2016 shows students practising wushu at the Tagou martial arts school in Dengfeng. China is investing hugely in football training and has vowed to have 50 million school- age players by 2020, as the ruling Communist party eyes “football superpower” status by 2050. (Photo by Nicolas Asfouri/AFP Photo)

A student from “the cliff village” in Atule'er climbs newly-constructed steel ladders after school to go home for holidays, in Liangshan Sichuan province, China, November 19, 2016. The steel ladders which replaced the unsafe vine ladders shortened the time taken for the children to go home, from three hours to two. (Photo by Reuters/Stringer)