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)

Grey seal pup “Nikolaus” licks a window at the seal enclosure in Friedrichskoog, Germany, 19 December 2014. The pup was abandoned by his mother and would not have a chance at survival without human help. Nikolaus will be fed at the enclosure for two to three months until he has reached the minimum weight of 45 kilograms for being released. (Photo by Daniel Reinhardt/EPA)

Fish are thrown onto a truck during a winter fishing festival held on the frozen Wulungu Lake in Fuhai county, Xinjiang Uighur Autonomous Region, January 18, 2015. (Photo by Reuters/China Daily)

A minaret, that was damaged during fighting between Islamic State jihadists and government forces, is seen in Ben Guerdane, near the Libyan border, Tunisia April 10, 2016. After a U.S. air strike killed a Tunisian jihadist commander in western Libya in late February, dozens of Islamic State fighters sneaked across the border into Tunisia and attacked an army barracks and police bases in the town of Ben Guerdane. (Photo by Zohra Bensemra/Reuters)

A Tamil devotee prays during the Thai Pongal harvest festival at a temple in Colombo January 15, 2016.The Tamil festival of Thai Pongal is a thanksgiving ceremony in which the farmers thank the spirits of nature, the sun and the farm animals for their assistance in providing a successful harvest. (Photo by Dinuka Liyanawatte/Reuters)

A protester gestures after he saw a dead protester in Kampala, Uganda February 15, 2016. At least one person has been killed in Uganda's capital Kampala as police clashed with opposition supporters after briefly detaining a top presidential candidate twice as he tried to hold campaign rallies days before a general election. Several people were wounded in the clashes as police fired bullets and tear gas while opposition supporters hurled rocks and erected street barricades in the capital's Wandegeya suburb, witnesses said according to a Reuters news agency report. (Photo by Goran Tomasevic/Reuters)

A boy collects drinking water from a hand pump in Kutubdia, Bangladesh on March 30, 2016. Kutubdia is one of many islands affected by some of the fastest recorded sea-level rises in the world. The island has halved in size in 20 years. (Photo by SIipa/Rex Features/Shutterstock)

A green iguana, or American iguana sits on an Aldabra giant tortoise, the largest tortoise of the world, in their enclosure at the zoo park of Lille, northern France, on February 11, 2019. (Photo by Philippe Huguen/AFP Photo)