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)

Residents of the Huachipa populous district, east of Lima, are helped on March 17, 2017, by police and firemen rescue teams to cross over flash floods hitting their neighbourhood and isolating its residents. The climatic phenomenon El Niño is causing muddy rivers overflows on the entire Peruvian coast, isolating hundreds of people, mostly residents of Lima's industrial belt neighbourhoods. (Photo by Cris Bouroncle/AFP Photo)

A sewer cleaner of Dhaka City Corporation cleaning out the city's sewers on May 03, 2017 in Dhaka, Bangladesh. Despite a rise in the number of deaths of manhole workers every year, workers regularly go into the manholes without any protective gear. (Photo by Zakir Chowdhury/Barcroft Images)

On the festival of Krishna Janmashtami, a girl costumed as Lord Krishna poses for a photo in Dhaka, Bangladesh on August 19, 2022. (Photo by Nayem Shaan/ZUMA Press Wire/Rex Features/Shutterstock)

A couple buy a sugar-coated Chinese haw to a child at the Qianmen pedestrian shopping street, a popular tourist spot in Beijing, Tuesday, January 3, 2023. (Photo by Andy Wong/AP Photo)

A deer canters past participants in the Darkness into Light event in Killarney, Co Kerry, Ireland on May 7th, 2022. The annual pre-dawn walk raises funds for Pieta, a charity that supports people who are in suicidal distress or engage in self-harm, as well as families affected by suicide. All counselling sessions and other services are provided free of charge. (Photo by James Crombie/INPHO)

A penguin (Manchots Royaux) walks on the basement area, early morning on December 25, 2022, at the Kerguelen Islands, also known as the Desolation Islands, are a group of islands in the sub-Antarctic. (Photo by Patrick Hertzog/AFP Photo)

US President Joe Biden departs the White House for California, where he will review damage from recent flooding, in Washington, DC, USA, 19 January 2023. (Photo by Jim Lo Scalzo/EPA/EFE)