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)

Sydney McLaughlin of Team United States celebrates with Legend the mascot after winning gold and setting a new world record in the Women's 400m Hurdles Final on day eight of the World Athletics Championships Oregon22 at Hayward Field on July 22, 2022 in Eugene, Oregon. (Photo by Hannah Peters/Getty Images for World Athletics)

Lee Kiefer of Team United States competes against Jessica Zi Jia Guo of Team Canada on Fencing - Women's Foil Individual at Parque Deportivo Panamericano on Day 10 of Santiago 2023 Pan Am Games on October 30, 2023 in Santiago, Chile. (Photo by Ezra Shaw/Getty Images)

A Chinese girl in traditional dress eats her lunch in a Five Guys restaurant in between shooting videos for her Chinese social media account on October 18, 2023 in London, United Kingdom. (Photo by Dan Kitwood/Getty Images)

Argentina's Clara Baiocchi pats Puerto Rico's Alondra Negron as she falls during the women's 3000-meters steeplechase final at the Pan American Games in Santiago, Chile, Saturday, November 4, 2023. (Photo by Fernando Vergara/AP Photo)

Competitors drive their homemade vehicle without an engine during the Red Bull Soapbox Race in Almaty, Kazakhstan on September 11, 2022. (Photo by Pavel Mikheyev/Reuters)

Portugal's Cristiano Ronaldo poses for a photo with Giuliana, a fan from Brazil, as he arrives with the Portuguese team at Lisbon airport to depart for the World Cup in Qatar, Friday, November 18, 2022. (Photo by Armando Franca/AP Photo)