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)

Vehicles move past a man wearing a protective mask against COVID-19 as he waits for the bus in Karachi, Pakistan on December 11, 2020. (Photo by Akhtar Soomro/Reuters)

Three prostitutes lean out of a window in Santiago, Chile, in an attempt to entice customers inside, circa 1950. (Photo by Three Lions/Getty Images)

This combination of April 15, 2013 and April 2, 2014 photos show a police officer clearing Boylston Street following a bomb blast near the finish line of the 2013 Boston Marathon, and pedestrians crossing at the same corner nearly a year later in Boston. (Photo by Charles Krupa/AP Photo)

A Rohingya migrant who arrived in Indonesia by boat cries while speaking on a mobile phone with a relative in Malaysia, at a temporary shelter in Kuala Langsa in Indonesia's Aceh Province May 16, 2015. Nearly 800 migrants were brought ashore in Indonesia on Friday, but other vessels crammed with them were sent back to sea despite a United Nations call to rescue thousands adrift in Southeast Asian waters with dwindling food and water. Thousands of Rohingya Muslims fleeing Myanmar and Bangladesh are stranded on boats as regional governments block them from landing. (Photo by Roni Bintang/Reuters)

Afghan child stands in front of a makeshift shelter after an earthquake in Gayan village, in Paktika province, Afghanistan, Friday June 24, 2022. A powerful earthquake struck a rugged, mountainous region of eastern Afghanistan early Wednesday, flattening stone and mud-brick homes in the country's deadliest quake in two decades, the state-run news agency reported. (Photo by Ebrahim Nooroozi/AP Photo)

Two young girls play near a makeshift tent where their family stay after the earthquake in Samandag, southern Turkey, Thursday, February 16, 2023. Ever since the Feb. 6 earthquake decimated swaths of Turkey and Syria, survivors have gathered outside destroyed houses and apartments, refusing to leave. (Photo by Francisco Seco/AP Photo)

English actress Michelle Keegan at “The Jonathan Ross Show” TV show, Series 18, Episode 7 in London, United Kingdom on December 4, 2021. (Photo by Brian J. Ritchie/Hotsauce/Rex Features/Shutterstock)