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)

Students from Langata primary school run past riot police as they protest against a perimeter wall illegally erected by a private developer around their school playground in Kenya's capital Nairobi January 19, 2015. Riot police used teargas to disperse students at a school in Nairobi as the children protested against the potential loss of their playground. The playground was fenced off in December, during the school holidays, by a prominent developer who also claims ownership of the land. The title to the contested site is said to be in the name of Airport View Housing Limited, according to local media, with plans to use the space to build a parking lot for a hotel. (Photo by Thomas Mukoya/Reuters)

Children, some in tears, are escorted down a road in Barcelona, Spain, Thursday, August 17, 2017. Police in Barcelona say a white van has mounted a sidewalk, struck several people in the city's Las Ramblas district. (Photo by Manu Fernandez/AP Photo)

A police officer fires his tear gas launcher during a clash with student protesters in Surabaya, East Java, Indonesia, Thursday, October 8, 2020. Thousands of enraged students and workers staged rallies across Indonesia on Thursday in opposition to the new law they say will cripple labor rights and harm the environment. (Photo by Trisnadi/AP Photo)

A police officer patrols as people party on a street as pubs shut for the night due to tier 3 restrictions in Soho, as the spread of the coronavirus disease (COVID-19) continues in London, Britain, December 15, 2020. (Photo by Henry Nicholls/Reuters)

Rajesh Babu, a police officer, wearing a helmet depicting coronavirus, requests a commuter to stay at home during a 21-day nationwide lockdown to limit the spreading of coronavirus disease (COVID-19), in Chennai, India, March 28, 2020. (Photo by P. Ravikumar/Reuters)

Participants approach a law enforcement officer with open arms during an opposition demonstration to protest against police violence and to reject the presidential election results near the Government House in Independence Square in Minsk, Belarus on August 14, 2020. (Photo by Vasily Fedosenko/Reuters)

An armed police officer checks the documents of a cyclist at a checkpoint placed to implement a curfew in the country's capital amid rising coronavirus disease (COVID-19) cases, in Caloocan City, Metro Manila, Philippines, March 16, 2021. (Photo by Eloisa Lopez/Reuters)