A Tengger tribesman prays at Mount Bromo during the annual Kasada ceremony in East Java on August 12, 2014. The Kasada ceremony is a festival held every 14th day of the Kasada month in the traditional Hindu lunar calender to honour Sang Hyang Widhi (God Almighty) and is based on the legend of Roro Anteng and Joko Seger from the Majapahit Kingdom, from which their Tengger tribe name originates. Hundreds of worshippers from the Tengger tribe offer food and livestock as a symbolic sacrifice which they throw into the crater for the blessings of safety and prosperity to their familyies and community. (Photo by Juni Kriswanto/AFP Photo)

A photo taken on August 29, 2014, shows Mount Tavurvur erupting in eastern Papua New Guinea, spewing rocks and ash into the air, forcing the evacuation of local communities and international flights to be re-routed. Mount Tavurvur, which destroyed the town of Rabaul when it erupted simultaneously with nearby Mount Vulcan in 1994, rumbled to life early in the morning on the tip of the remote island of New Britain. (Photo by Oliver Bluett/AFP Photo)

Members of the Russian Red Army Choir perform at Water Front Theatre in Beirut September 13, 2014. (Photo by Jamal Saidi/Reuters)

A heat-stressed koala waits as a resident pours water on its back on December 19, 2015 in Adelaide, Australia. Adelaide is experiencing an extreme heatwave, with temperatures reaching over 40 degrees for five consecutive days. (Photo by Morne de Klerk/Getty Images)

People stand around a leopard with its head stuck in a vessel in Rajsamand district of Rajasthan state, India, Wednesday, September 30, 2015. The leopard's head got stuck when it attempted to drink water from the pot, according to news reports. Forest officials tranquilized the animal and sawed off the vessel later in the day. (Photo by Kabir Jethi/AP Photo)

Iraqi firefighters try to stop the fire of burning oil wells in Kirkuk, northern Iraq, 02 June 2016. Two Khabbaz oil field wells in Kirkuk Province, northern Iraq, exploded by suspected insurgents, a security official said. (Photo by EPA/Stringer)

Reflected in an ornament, a reporter takes a photo of the White House Christmas Tree in the Blue Room during a media preview of the holiday decor at the White House in Washington, U.S., November 29, 2016. (Photo by Kevin Lamarque/Reuters)

An airplane is silhouetted at sunrise, seen from the suburb of Saint-Cloud, near Paris, France, 08 December 2016. Paris is undergoing a third day pollution spike, prompting the city to limit vehicle circulation. (Photo by Ian Langsdon/EPA)