Hot air balloons take to the skies over Bristol city centre on August 6, 2012 in Bristol, England. The early morning flight of over twenty balloons over the city was organised as a curtain raiser for the four-day Bristol International Balloon Fiesta which starts on Thursday. Now in its 34th year, the Bristol International Balloon Fiesta is Europe's largest annual hot air balloon event in the city that is seen by many balloonists as the home of modern ballooning. (Photo by Matt Cardy)

People sit on the top of a truck heavily piled with corn-stalks plies as they head for Mogadishu from Afgooye on October 19, 2016. At least four police officers were killed on October 18 when a suicide bomb attacker rammed an explosives-packed car into a police station before fighters from the Al-Qaeda-linked Shabaab group subsequently stormed the area killing at least 10 people, including soldiers and civilians. (Photo by Mohamed Abdiwahab/AFP Photo)

A Naga sadhu, or naked Hindu holy man, performs a ritual inside his tent during Kumbh Mela, or Pitcher festival, at Trimbakeshwar, India, Friday, August 28, 2015. Hindus believe taking a dip in the waters of a holy river during the festival will cleanse them of their sins. The festival is held four times every 12 years. (Photo by Rajanish Kakade/AP Photo)

Hot air balloons take to the skies as they participate in the mass assent at sunrise on the second day of the Bristol International Balloon Fiesta on August 11, 2017 in Bristol, England. More than 130 balloons have gathered for the four day event, now in its 39th year and now one of Europe's largest annual hot air balloon events, being hosted in the city that is seen by many as the home of modern ballooning. (Photo by Matt Cardy/Getty Images)

Olivia Love-Hatlestad of Grayslake, IL., stands during the second day of the Democratic National Convention at the Wells Fargo Center, July 26, 2016 in Philadelphia, Pennsylvania. An estimated 50,000 people are expected in Philadelphia, including hundreds of protesters and members of the media. The four-day Democratic National Convention kicked off July 25. (Photo by Drew Angerer/Getty Images)

A four-year-old dog Nika stands next to an image of Cuba's revolutionary hero Ernesto “Che” Guevara in front of a flooded street in Havana, January 23, 2016. Havana's seafront Malecon continued to be slammed by massive waves that flooded parts of the seaside city on Saturday. As a result, Havana was confronting flooding as a cold front passes through the Caribbean island. The giant waves began washing up onto shore during sunrise. The waves have been accompanied by winds passing through at a speed between 35 and 50 km (21 to 31 miles) per hour. (Photo by Alexandre Meneghini/Reuters)

Four hundred buyers from around the world join 260 diamond manufacturing and trading firms on International Diamond Week as some 1,500 people are expected to trade more than billion of polished diamonds this week in Ramat Gan, Israel on February 16, 2016. The Israel Diamond Exchange is considered the most secure in the world, covering an area of 100,000 square meters with 3,500 bourse members. (Photo by Nir Alon via ZUMA Wire)

Sculptures entitled “The Rising Tide” by British sculptor Jason deCaires Taylor are seen beside the River Thames in front of the Houses of Parliament and the London Eye ferris wheel in London, September 3, 2015. The representations of four horses and riders are fully visible at low tide but become immersed underwater twice a day as the Thames rises to reach full tide. The installation will be on display throughout September as part of the annual Totally Thames festival. (Photo by Toby Melville/Reuters)