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 military police officer aims his gun to a demonstrator during a protest in Brasilia, Brazil, Tuesday, April 7, 2015. The officer had picked up a bottle that was thrown towards them but did not fire his gun and backed away. Thousands of workers have staged rallies in 12 cities across Brazil to protest against a proposed law that would allow companies to outsource their labor force. (Photo by Eraldo Peres/AP Photo)

Spacewalker Mark Vande Hei took his own photograph during the first spacewalk of 2018, on January 23, 2018. These sky-high pictures are better known as “space-selfies”. (Photo by Mark Vande Hei/NASA)

Aegean airlines air hostesses take selfies after a news conference in Athens, Wednesday, March 28, 2018. In a deal worth up to $5 billion, Greek airline Aegean says it will buy 30 new Airbus aircraft, with the option of an additional 12, to upgrade its fleet as the country expects to break tourism records. The signing of the final purchase agreement is expected in June. (Photo by Petros Giannakouris/AP Photo)

Tourists pose for photos at the Skybox at Kuala Lumpur Tower in Kuala Lumpur, Malaysia, Wednesday, July 1, 2020. Malaysia entered the Recovery Movement Control Order (RMCO) after three months of coronavirus restrictions. (Photo by Vincent Thian/AP Photo)

A girl wears a face mask to curb the spread of the coronavirus as she attends a prayer ceremony to mark the holiday of “Enkutatash”, the first day of the new year in the Ethiopian calendar, which is traditionally associated with the return of the Queen of Sheba to Ethiopia some 3,000 years ago, at Bole Medhane Alem Ethiopian Orthodox Cathedral in the capital Addis Ababa, Ethiopia Friday, September 11, 2020. (Photo by Mulugeta Ayene/AP Photo)

Drinkers leave the bars as police patrol in Soho, in central London on September 24, 2020 as the clock nears 10pm, on the first day of the new earlier closing times for pubs and bars in England and Wales, introduced to combat the spread of the coronavirus. Britain has tightened restrictions to stem a surge of coronavirus cases, ordering pubs to close early and advising people to go back to working from home to prevent a second national lockdown. (Photo by Tolga Akmen/AFP Photo)

A child in a Supergirl costume pays respects as Justice Ruth Bader Ginsburg lies in repose under the Portico at the top of the front steps of the U.S. Supreme Court building, in Washington, U.S. September 23, 2020. (Photo by Alex Brandon/Pool via Reuters)