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)

A man is silhouetted in front of the Allianz-Arena as he walks his dogs at sunrise in Munich, southern Germany, Friday, April 10, 2015. (Photo by Peter Kneffel/AP Photo/DPA)

A local boy plays football on Iracema Beach on June 11, 2014 in Fortaleza, Brazil. (Photo by Robert Cianflone/Getty Images)

An Afghan man rides on his donkey, holding balloons for sale during Newroz Day celebrations, a festival marking their spring and new year, in Kabul, Afghanistan March 21, 2017. (Photo by Omar Sobhani/Reuters)

Japanese chorus girls appear to be drilling in military tactics atop their theater building as they perform salutes, June 30, 1937. The officer is from the Japanese regular army and says the girls display more rhythm in their drills than do the regular troops. (Photo by AP Photo)

Alligators and an egret stand on the banks of the Bento Gomes river next to the Transpantaneira road at the Pantanal wetlands near Pocone, Mato Grosso state, Brazil, Monday, September 14, 2020. A vast swath of the vital wetlands is burning in Brazil, sweeping across several national parks and obscuring the sun behind dense smoke. (Photo by Andre Penner/AP Photo)

Villagers riding a rickshaw maneuver along an overflowing dam at the border between Cavite province and Las Pinas city, in Las Pinas, Philippines, 25 October 2020. According to Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA), Typhoon Molave will make landfall in the evening of 25 October in southern Luzon island. An alert was issued to residents for possible floods and landslides. (Photo by Francis R Malasig/EPA/EFE)

A motorcycle carrying a pig crosses a flooded road in Albay province, central Philippines due to Typhoon Vamco on Thursday, November 12, 2020. (Photo by John Michael Magdasoc/AP Photo)