Revellers celebrate "Ash Monday" by participating in a colourful "flour war", a traditional festivity marking the end of the carnival season and the start of the 40-day Lent period until the Orthodox Easter,in the port town of Galaxidi, some 215 km (134 miles) north west of Athens, March 18, 2013. The revellers "fight" by throwing coloured flour, charcoal dust and powder painting until they essentially run out of supplies. (Photo by Yannis Behrakis/Reuters)

Kent Josephso organizes his 8mm tracer rounds during the Big Sandy Shoot in Mohave County, Arizona March 23, 2013. The Big Sandy Shoot is the largest organized machine gun shoot in the United States attended by shooters from around the country. Vintage and replica style machine guns and cannons are some of the weapons displayed during the event. Picture taken March 22, 2013. (Photo by Joshua Lott/Reuters)

A life-size interactive inflatable sculpture of Stonehenge called “Sacrilege 2012” by English contemporary artist Jeremy Deller on display as part of the “Inflation!” exhibition curated by Mobile M + on April 24, 2013 in Hong Kong. The inflatable artwork is one of six on display as part of the exhibition which is open from April 25, 2013 until June 9, 2013. (Photo by Jessica Hromas)

A girl in a vamire costume poses for pictures during the traditional park picnic on the first day of the annual Wave-Gotik Treffen, or Wave and Goth Festival, on May 17, 2013 in Leipzig, Germany. The four-day festival, in which elaborate fashion is a must, brings together over 20,000 Wave, Goth and steam punk enthusiasts from all over the world for concerts, readings, films, a Middle Ages market and workshops. (Photo by Marco Prosch)

Vernon Yates, founder of Wildlife Rescue and Rehabilitation, lays his hands on Ty, a 400-pound tiger, as staff prepare to surgically extract a 4-pound hairball from the big cat, in Clearwater, Florida, on May 22, 2013. Ty is cared for by Wildlife Rescue and Rehabilitation in Seminole. The non-profit animal rescue group mainly serves by assisting Florida law enforcement with animals that have been seized. (Photo by James Judge/Courtesy BluePearl Veterinary Partners)

Residents, covered with mud and dried banana leaves, ask for money and candles from police before attending a mass celebrating the feast day of the Catholic patron Saint John the Baptist in the village of Bibiclat, Nueva Ecija, north of Manila, June 24, 2013. Hundreds of devotees took part in this annual religious tradition, which has been held in the village since 1945. (Photo by Cheryl Ravelo/Reuters)

Pope Francis greets the crowd from his popemobile in downtown Rio de Janeiro. Pope Francis touched down in Rio de Janeiro on Monday, starting his first foreign trip as pontiff and a weeklong series of events expected to attract more than a million people to a gathering of young faithful in Brazil, home to the world's largest Roman Catholic population. (Photo by Ueslei Marcelino/Reuters)

Tourists play at a beach covered by a thick layer of green algae in Qingdao, China, on July 3, 2013. A large quantity of non-poisonous green seaweed, enteromorpha prolifera, hit China's Qingdao coast last month. More than 20,000 tons of such seaweed has been removed from the city's beaches. This has now become an annual summer event. (Photo by Whitehotpix/ZumaPress.com)