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