Al-Shabab recruits walk down a street on March 5, 2012, in the Somalian capital, Mogadishu, following their graduation. The militant group has transformed from being just a Somali group to a regional network in East Africa. Mohamed Abdiwahab/AFP/Getty Images hide caption

itoggle caption Mohamed Abdiwahab/AFP/Getty Images

Students gather at a distance from the Garissa University College after an attack by gunmen in Garissa, Kenya, Thursday. The attack has injured dozens of people; a siege is ongoing. AP hide caption

itoggle caption AP

Customers wait to collect money at the Juba Express money transfer company in Mogadishu, Somalia, on Feb. 12. Mohamed Abdiwahab/AFP/Getty Images hide caption

itoggle caption Mohamed Abdiwahab/AFP/Getty Images

Somali-American youths play basketball before the start of a September 2013 solidarity rally by the Minneapolis Somali community to denounce al-Shabab's attack of a shopping mall in Nairobi, Kenya. Less than a decade after groups of teens from Minneapolis emigrated to Somalia to join the terrorist group, more have been recruited to join the self-declared Islamic State in Syria. Eric Miller/Reuters/Landov hide caption

itoggle caption Eric Miller/Reuters/Landov

Ahmed Ismail, a soccer coach, runs the West Bank Athletic Club in Minneapolis. His players practice near a large Somali community where young people have been recruited to fight in overseas conflicts. Craig Lassig/AP hide caption

itoggle caption Craig Lassig/AP

Yemeni soldiers hold up their weapons at an area seized from al-Qaida in the southeastern province of Shabwa, Yemen, on May 8. President Obama said Wednesday that U.S. strategy against the so-called Islamic State would be similar to how it targeted militants in Yemen and Somalia. Yemen's Defense Ministry/AP hide caption

itoggle caption Yemen's Defense Ministry/AP

Friends and relatives of Mbugua Mwangi and his fiancee Rosemary Wahito attended their funeral service Friday in Nairobi, Kenya. Mwangi, who was Kenyan President Uhuru Kenyatta's nephew, and Wahito died in the Westgate Mall attack. Jerome Delay/AP hide caption

itoggle caption Jerome Delay/AP

Kenyans watch Monday as a plume of black smoke rises over the Westgate Mall, scene of a terrorist attack that left more than 60 dead. Kenya is a crossroads in East Africa, has many links to the West and has sent troops into Somalia. For all these reasons, the country was targeted by Somalia's al-Shabab militia group. Ben Curtis/AP hide caption

itoggle caption Ben Curtis/AP

Kenyan police officers take cover outside the Westgate mall in Nairobi on Monday. Simon Maina /AFP/Getty Images hide caption

itoggle caption Simon Maina /AFP/Getty Images

Heavy smoke rises from the Westgate Mall in Nairobi, Kenya, on Monday. The Somali militant group al-Shabab claimed responsibility for the attack. Jerome Delay/AP hide caption

itoggle caption Jerome Delay/AP

Kenyan soldiers outside the Westgate shopping mall in Nairobi on Monday. Inside, attackers had killed dozens of shoppers, wounded more and it was feared they also had hostages. Daniel Irungu /EPA/Landov hide caption

itoggle caption Daniel Irungu /EPA/Landov