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)

A Somali police officer arrests a suspected rebel member of the al Qaeda-affiliated al Shabaab among beach goers in Mogadishu. Al Shabaab claimed responsibility for today's pre-dawn attack on a Kenyan university campus near the Somali border. The following gallery examines who is al Shabaab. Here: Somali police officer (R) arrests a suspected rebel member (L) of the Al Qaeda-affiliated al Shabaab among beach goers at the Lido beach north of Somalia's capital Mogadishu March 23, 2012. (Photo by Feisal Omar/Reuters)

In this January 4, 2016 photo, the weapon of a rebel fighter for the 36th Front of the Revolutionary Armed Forces of Colombia, or FARC, hangs from a branch serving as a makeshift clothesline, near a rebel camp, in Antioquia state, in the northwest Andes of Colombia. “We’ll lay aside our weapons, like the accord says, but never hand them over”, says Juan Pablo, a commander of the 36th Front. (Photo by Rodrigo Abd/AP Photo)

In this September 27, 2017 file photo, girls walk past a wall riddled with bullet holes from shootings between rival drug traffickers, at the Rocinha slum, in Rio de Janeiro, Brazil. Violence is on the rise in Rio's slums after several years of decline, and the killings of kids have shocked even residents long inured to deaths from gangs and police. (Photo by Silvia Izquierdo/AP Photo)

Rohingya refugees stand outside of their refugee camp on February 11, 2017 in Medan, North Sumatra, Indonesia. Thousands of Rohingya Muslims have been stuck in limbo at Indonesia's refugee camps as the plight of Myanmar's ethnic minority continues. (Photo by Ulet Ifansasti/Getty Images)

A sewer cleaner of Dhaka City Corporation cleaning out the city's sewers on May 03, 2017 in Dhaka, Bangladesh. Despite a rise in the number of deaths of manhole workers every year, workers regularly go into the manholes without any protective gear. (Photo by Zakir Chowdhury/Barcroft Images)

Aerial photo taken on April 20, 2018 shows the view of advection fog above Qingdao, a coastal city in east China' s Shandong Province. (Photo by Lu Hui/Xinhua News Agency/Eyevine)

Cyclists desperately try to keep their heavily-laden bicycles upright as they arrive at a market with baskets full of pineapples on August 23, 2018. The men travel up to 12 and a half miles with two baskets tied to the sides of their bikes, carrying between 50 and 100 pineapples to sell. Each of the bicycles is so heavily laden with fruit it is impossible for the men to actually ride their bikes, instead having to walk alongside them. When they arrive at the market place in Madhupur, Bangladesh, buyers will pay up to 30 Taka for a pineapple – the equivalent of around 28 pence. (Photo by Abdul Momin/Solent News & Photo Agency UK)