Al-Shabaab, the militant Islamist group, issued a claim of responsibility on its website and said it killed Somali and Ethiopian troops, who have been fighting Al-Shabaab.
MORE: http://www.cnn.com/2013/10/19/world/africa/somalia-unrest/index.html
See also...
Al-Shabaab grew amid Somalia's lawlessness
http://www.cnn.com/2013/10/05/world/africa/somalia-al-shabaab-explainer/index.html
