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 young bull flees from a Brazilian vaqueiro, or cowboy, competing in the “Pega de Boi” (Ox Catch) tournament in Cabrobo, Pernambuco State, Brazil, on September 4, 2022. The riders compete in pairs to retrieve a cord from a bull which has been released and runs away from them and they are timed on how quickly they can return with the cord. The leather clothing provides them with protection from the dense savannah vegetation which contains a lot of large thorns. Riders have been known to die competing in the tournament (Photo by Carl de Souza/AFP Photo)

Russian soldiers run along Red Square in central Moscow on September 29, 2022, as the square is sealed prior to a ceremony of the incorporation of the new territories into Russia. Russia will formally annex four territories of Ukraine its troops occupy at a grand ceremony in Moscow on Friday, the Kremlin has announced, after Russia suggested it could to use nuclear weapons to defend the territories. (Photo by Alexander Nemenov/AFP Photo)

A United States Secret Service agent fights with the wind as Marine One with United States President Joe Biden on board departs from the White House in Washington to Ottawa, Canada on March 23, 2023. (Photo by Rex Features/Shutterstock)

Starting on Monday, August 12, Perseid meteors will streak across the summer sky for a couple of nights, offering casual stargazers and serious nighttime photographers a chance to capture a glimpse of the annual meteor shower. Photo: Photographer David Kingham created this composite image from 23 photos on August 12, 2012. (Photo by David Kingham)

Girls prepare to take part in a mermaid lesson in Rio de Janeiro, Brazil May 28, 2017. Women in Brazil are not unique in their affinity for mermaiding. Classes are held as far away as Texas and some folks wonder if mermaiding will be the next fitness craze. (Photo by Pilar Olivares/Reuters)

“After the death of a teenager (14-year-old Elijah Doughty), hundreds of Indigenous locals took to the streets of Kalgoorlie to vent their anger. Danella Bevis captures the grief and outrage of a family and a community. There is raw aggression in an eruption of racial tensions and violence, and in stark contrast she concludes the narrative with a moment of quiet beauty at a dusk vigil”. (Photo by Danella Bevis/The Walkley Foundation)

In this photo taken Tuesday, June 23, 2015, a Ukrainian serviceman from the Kiev-2 volunteer battalion fires an weapon at a frontline in the village of Krymske, east Ukraine. Few places along the front line in east Ukraine see regular fighting as bitter as the village of Krymske. For now, Krymske is in the hands of Ukrainian government forces and the volunteer battalions that fight alongside them. (Photo by Evgeniy Maloletka/AP Photo)