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)

ESA astronaut Samantha Cristoforetti on the International Space Station 3 February 2015 during her Futura mission. Samantha is living and working on the Station as part of the Expedition 42 crew. Picture released on February 10, 2015. (Photo by ESA/NASA)

Camille Kovalev and Pavel Kovalev of France compete in the Pairs Short Program during the ISU World Figure Skating Championships at Saitama Super Arena on March 22, 2023 in Saitama, Japan. (Photo by Kim Kyung-Hoon/Reuters)

Libyan leader Muammar Gaddafi attends the inauguration ceremony of Jacob Zuma on May 9, 2009 in Pretoria, South Africa. Jacob Gedleyihlekisa Zuma is South Africa's fourth President since the end of apartheid. (Photo by Foto24/Gallo Images/Getty Images)

An Indian Hindu married woman offers prayers during Karva Chauth festival in Jammu, India, Sunday, October 24, 2021. Hindu married women decorate their hands with henna, wear colorful bangles and observe a fast to pray for the longevity and well being of their husbands during this festival. (Photo by Channi Anand/AP Photo)

Kyla Drumm, 5, waits after receiving the Pfizer-BioNTech coronavirus disease (COVID-19) vaccine in Skippack, Pennsylvania, U.S., November 3, 2021. (Photo by Hannah Beier/Reuters)

Fabian Ramirez, 11, scavenges a trash container for vegetables with his family that were discarded at the “Mercado de Abasto”, a market for vendors, during the fourth week of a quarantine to help contain the spread of the new coronavirus in Asuncion, Paraguay, Thursday, April 2, 2020. (Photo by Jorge Saenz/AP Photo)

Young women wearing facemasks and traditional costumes of Song dynasty and Tang dynasty are seated on a bench in a park next to the East Lake in Wuhan, in China’s central Hubei province on May 17, 2020. The Guardian picture desk has chosen on December 17, 2020, the AFP photojournalist Hector Retamal as “Agency Photographer of the Year 2020” for his coverage of the novel coronavirus Covid-19 pandemic in Wuhan, China. (Photo by Hector Retamal/AFP Photo)