Tourists look at other festival-goers playing in the mud during the Boryeong Mud Festival at Daecheon beach in Boryeong, about 190 km (118 miles) southwest of Seoul, July 19, 2013. About 2 to 3 million domestic and international tourists visit the beach during the annual mud festival, according to the festival organisers. (Photo by Lee Jae-Won/Reuters)

A general view showing the shipwrecked cruise ship Costa Concordia in an upright position after the salvage operations in Giglio island, Italy, 17 September 2013. Salvage crews pulled off a major engineering feat when they straightened the listed Costa Concordia cruise ship from the rocks it had been wedged against for the past 20 months. The delicate operation took 19 hours and was completed at 4 am (0200 GMT). The vessel ran aground near the island of Giglio, in Tuscany, in an accident that made world-wide news. (Photo by Angelo Carconi/EPA)

A pro-democracy demonstrator fights with a Soviet soldier on top of a tank parked in front of the Russian Federation building on August 19, 1991, after a coup toppled Soviet President Mikhail Gorbachev. The same day, thousands in Moscow, Leningrad, and other cities answered Russian Republic President Boris Yeltsin's call to raise barricades against tanks and troops. (Dima Tanin/AFP/Getty Images)

Damai, 3 years old Bornean orang utan plays courtyard at Surabaya Zoo as he prepares to be released into the wild on May 19, 2014 in Surabaya, Indonesia. The two baby orangutans, brothers, were found in Kutai National Park in a critical condition having been abandoned by their mother on May 14, 2014. The Centre for Orangutan Protection (COP) have since been nursing the animals back to health, treating them for malnourishment and 16 wounds predominantly to the feet and hands. (Photo by Robertus Pudyanto/Getty Images)

Protestor Bill Maloney (L) shouts during a live TV broadcast by BBC News Channel chief political correspondent Norman Smith after earlier forcing Deputy Prime Minister Nick Clegg to abandon a photocall near Parliament on March 19, 2014 in London, England. The Chancellor of the Exchequer, George Osborne has delivered his Budget statement to Members of Parliament in the House of Commons. (Photo by Peter Macdiarmid/Getty Images)

Migrants climb through the windows of a train bound for Serbia at the train station in Gevgelija, The Former Yugoslav Republic of Macedonia, 19 July 2015. Thousands of migrants who crossed Greece are on their way through Macedonia towards Serbia in order to access other European countries. Hungary in mid-July started to put up a fence on its border with Serbia, which makes the situation with the migrants in the transit countries even more complicated. The European countries on 20 July will discuss the quota of how many migrants each country should accept. (Photo by Georgi Licovski/EPA)

A clown plays the violin during the XXI Convention of Clowns, at the Jimenez Rueda Theatre, in Mexico City, Mexico, October 19, 2016. In the wake of the creepy clown sightings in several states of North and South Americas and Europe that caused widespread panic, professional clowns from across Latin America came together at an annual convention in Mexico to give a serious message: “We are clowns, not killers!”. Around 200 clowns took part in the 21st International Clown Convention, dressed in bright coloured clothes and makeup, and chanted the word as they clicked group pictures to counter the “creepy clown” craze. (Photo by Carlos Jasso/Reuters)