Shabab militants attacked an upscale mall in Nairobi, Kenya, beginning on Sept. 21, 2013, killing nearly 70 people and wounding about 175. The siege lasted for four days, with persistent fighting between government troops and militants. The attack was meticulously planned, and the militants proved to be challenging for the government to dislodge from the Westgate mall. Shabab said the attack was in retaliation for the Kenyan militarys presence in Somalia.

Days after the siege ended, U.S. Navy SEALs stormed a villa in Somalia in pursuit of an Al Shabab leader who goes by the name Ikrimah. The commandos were met with strong resistance and engaged in a gun battle with militants before retreating without capturing or killing Ikrimah. U.S. officials did not link Ikrimah to the attack in Nairobi, but did say he is one of the militants in charge of planning attacks outside Somalia and that he was connected to members of Al Qaeda who masterminded the 1998 attack on the American Embassy in Nairobi, Kenya.