During the summer of 2011 , the East African region faced a drought and shortage of food supplies , particularly in the Somali region , forcing tens of thousands of people to cross the borders into Ethiopia and Kenya for refuge . Al-Shabaab threatened to expel the aid groups working in the area before the African Union 's AMISOM troops took action to force the Al-Shabaab fighters out of the region . In July 2010 , Al-Shabaab also claimed responsibility for a bombing in Kampala , Uganda , in retaliation for Uganda 's support to , and presence in , AMISOM
bombing
July 2010 Kampala attacks
2011 Mogadishu bombing