Paramilitary policemen take part in a training in Chaohu, Anhui province, China December 28, 2015. (Photo by Reuters/China Daily)

Girls rest on stairs at the China Digital Entertainment Expo and Conference (ChinaJoy) in Shanghai, China July 27, 2017. (Photo by Aly Song/Reuters)

People hold umbrellas as they walk past a flooded street in Taiyuan, Shanxi Province, China, July 19, 2016. (Photo by Reuters/China Daily)

A girl jumps over a campfire while celebrating Ivan Kupala Night, a traditional Slavic holiday not far from Kiev on July 6, 2013. During the celebration, originating in pagan times, people plait wreaths, jump over fires, and swim naked. (Photo by Sergei Supinsky/AFP Photo)

Ultra-Orthodox Jews dance next to a bonfire during celebrations for the Jewish holiday of Lag Ba-Omer in Jerusalem's Mea Shearim neighbourhood May 25, 2016. This day marks the hillula (celebration, interpreted by some as anniversary of death) of Rabbi Shimon bar Yochai, a Mishnaic sage and leading disciple of Rabbi Akiva in the 2nd century, and the day on which he revealed the deepest secrets of kabbalah in the form of the Zohar (Book of Splendor), a landmark text of Jewish mysticism. (Photo by Ronen Zvulun/Reuters)

Pakistani passengers ride on crowded train returning from their hometown and villages after celebrating the Eid al-Fitr holiday to mark the end of the Muslim holy fasting month of Ramadan, to Lahore, Pakistan, Monday, July 11, 2016. (Photo by K.M.Chaudary/AP Photo)

Tourists ice skate at night on the Eiffel Tower's skating rink in Paris December 9, 2014. The skating rink, located on the first level of the Eiffel Tower, opens to the public as part of the Christmas holiday season. (Photo by Charles Platiau/Reuters)

Ukrainians swim in an ice hole as part of the celebration of the Epiphany in Kiev, Ukraine, Monday, January 19, 2015. Orthodox believers celebrate the holiday of the Epiphany on Jan. 19, and traditionally bathe in holes cut through thick ice on rivers and ponds to cleanse themselves with water deemed holy for the day. (Photo by Sergei Chuzavkov/AP Photo)