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)

Passengers embrace each other at the entrance to Istanbul's Ataturk airport, early Wednesday, June 29, 2016 following their evacuation after a blast. Suspected Islamic State group extremists have hit the international terminal of Istanbul's Ataturk airport, killing dozens of people and wounding many others, Turkish officials said Tuesday. (Photo by Emrah Gurel/AP Photo)

Jerome Holcomb of Birmingham, Ala., posses for a photo atop a longhorn steer at the Fort Worth Stockyards Thursday, March 11, 2021, in Fort Worth, Texas. The mask mandate to prevent the spread of COVID-19 has been cancelled in Texas. Holcomb said he was tired of wearing a face mask so he came to visit Fort Worth after the Alabama governor extended the mask mandate in his home state. (Photo by L.M. Otero/AP Photo)

Kerry Katona carries Peter McDonagh's flag before he faces Peter Krame during their Super welterweight bout at the Bolton Whites Hotel, Bolton, United Kingdom on May 12, 2018. (Photo by Lee Smith/Action Images via Reuters)

A demonstrator gestures as she talks with a Lebanese army member during a protest as Lebanon marks the two-year anniversary of the August 2020 Beirut port explosion, in Beirut, Lebanon on August 4, 2022. (Photo by Mohamed Azakir/Reuters)

People wade through a flooded path near Sangam, the confluence of the Ganges, Yamuna and mythical Saraswati rivers after the water level of river Ganges and river Yamuna rose, in Allahabad on October 14, 2022. (Photo by Sanjay Kanojia/AFP Photo)

A policeman stands near a burning vehicle during clashes between supporters of former prime minister Imran Khan and riot police near Khan's house to prevent officers from arresting him, in Lahore on early March 15, 2023. Pakistan police appeared on March 15 to have given up an attempt to arrest former prime minister Imran Khan, ending a siege of his residence after violent clashes with hundreds of his supporters. (Photo by Arif Ali/AFP Photo)

Derby's Byron MacLean, left, edges out Hall's Joe Nham in the boys 55-meter hurdles at the CIAC State Open indoor track championships at the Floyd Little Athletic Center in New Haven, Saturday, February 17, 2024. Lyman Hall's Owen Rich, right, falls after taking down the final hurdle. (Photo by Cloe Poisson/Hartford Courant via AP Photo)